I came across the maths for this on 1d4chan, so take it with a grain of salt, but these are
the math hammer stats for Guilliman vs the other Primarchs (who have
rules). Has Forge World cracked the blue pepper grinder?
Roboute Guilliman VS Horus
Horus will use his Talon of Horus (Rerollable 3+ is better than flat 2+, and Disabling Strike can counter the slow-burn effect of Preternatural Strategy) and hits 4 times, wounds 3.555 times, 1.778 after saves, than 1.278 for the Armor of Reason and IWND will take that down to 0.944 wounds at the start of the next turn.
Guilliman hits 2.5 times, wounds 2.222 times (Gladius), 0.74 wounds after saves and IWND will take that down to 0.4.
Guilliman loses this fight (Quite appropriately).
Note: Due to the nature of the fight this match doesn't take into account Preternatural Strategy (Because is balanced by Disabling Strike). Also do note that after the first few wounds inflicted from Horus Guilliman will have his WS and S significantly reduced, making it even easier for Horus to win.
Roboute Guilliman VS Angron
Angron Round 1: Angron has Hatred, so on the first turn he will hits 5.333 times, wounds 4.444 times, 2.222 after saves, 1.722 after Armor of Reason re-roll and IWND take it down to 1.388.
Angron Round 2: Angron hits 4 times, wounds 3.333 times, 1.667 times after saves, 1.167 after re-roll and IWND will take that down to 0.833 wounds at the start of the next turn.
Angron Round 3 and thereafter: Angron hits 3 times, wounds 2.5 times, 1.25 after saves and 0.75 after re-roll. Then IWND take it down to 0.417
Guilliman Round 1/2/3: hits 2.5 times, wounds 2.222 times, 0.926 times after saves and FNP, and IWND will take that down to 0.59 wounds at the start of the next turn.
Guilliman Round 4 and thereafter: hits 3.333 times, wounds 2.963 times, 1.234 times after saves and FNP, and IWND will take that down to 0.9 wounds at the start of the next turn.
Surprisingly, Guilliman win this fight in 8 rounds (Angron need 11 to kill him), 'for his resilience (Armour of Reason) coupled with Preternatural Strategy makes him outdamage Angron on the long run, even though initially it was the Red Angel to have the edge.
Roboute Guilliman VS Fulgrim
Fulgrim Round 1: hits 5.333 times (Fireblade is MC), wounds 3.555 times, 1.278 times after saves and IWND will take that down to 0.944 at the start of the next turn.
Fulgrim Round 2 and thereafter: hits 4 times, wounds 2.667 times, 0.8333 times after saves and IWND will take that down to 0.5 at the start of the next turn
Guilliman Round 1/2: hits 2.5 times, wounds 2.222 times, 0.74 times after saves and IWND will take that down to 0.407 wounds at the start of the next turn.
Guilliman Round 3 and thereafter: hits 3.333 times, wounds 2.963 times, 0.988 times after saves and IWND will take that down to 0.654 wounds at the start of the next turn.
Another surprising victory, even if by a small margin: Papa Smurf needs only 10 turns to kill Fulgrim, while Fulgrim needs 11.
Note: Actually, Guilliman has a lot more chances to kill him while surviving using the Hand of Dominion, Concussing Fulgrim to Initiative 1 will make him lose all his advantages, making him only deal 0.1667 wounds per round, after all calculations. But I used the Gladius as reference in the off chance he didn't inflict at least a wound per turn (only 7% chance per turn after Round 3, but Alas).
Roboute Guilliman VS Mortarion
Mortarion hits 2.5 times, wounds 1.666, 0.333 wounds after saves and after IWND they become 0 wounds
Guilliman Round 1: hits 2.5 times, wounds 2.083 times, 1.042 after saves, and IWND take it down to 0.486.
Guilliman Round 2 and after: hits 3.333 times, wounds 2.777 times, 1.388 times after saves and IWND will take that down to 0.833.
Easy win for Guilliman, as Mortarion cannot hurt him at all mathematically.
Roboute Guilliman VS Ferrus
Ferrus: hits 2.5 times, wounds 2.083 times (Forgebreaker and Servo-Harm), 0.542 times after saves and IWND will take that down to 0.208 at the start of the next turn.
Guilliman Round 1: hits 2.5 times, wounds 2.083 times (Hand), 0.694 times after saves and IWND will take that down to 0.361 wounds at the start of the next turn.
Guilliman Round 2 and thereafter: hits 3.333 times, wounds 2.778 times, 0.926 times after saves and IWND will take that down to 0.593 wounds at the start of the next turn.
Guilliman win this fight.
Roboute Guilliman VS Konrad Curze
Curze Round 1: hits 4 times, wounds 3 times, 1 times after saves and IWND will take that down to 0.667 at the start of the next turn.
Curze Round 2 and thereafter: hits 3 times, wounds 2.25 times, 0.625 times after saves and IWND will take that down to 0.292 at the start of the next turn
Guilliman Round 1/2: hits 2.5 times, wounds 2.222 times, 1.111 times after saves and IWND will take that down to 0.778 wounds at the start of the next turn.
Guilliman Round 3 and thereafter: hits 3.333 times, wounds 2.963 times, 1.481 times after saves and IWND will take that down to 1.148 wounds at the start of the next turn.
Guilliman easily win this fight.
Note: Konrad could attempt to even the odds with Hit and Run, negating Preternatural Strategy while gaining the +1 attack for the charge (and sniping some wounds with his knives). But so long as Guilliman uses his power fist by the second round of combat Curze will be locked to initiative 1 and will be dead before it's guaranteed he'll be able to leave combat.
Roboute Guilliman VS Vulkan
Vulkan hits 2 times, wounds 1.667 times, 0.3333 times after saves and IWND will take that down to 0.
Guilliman Round 1: hits 2.5 times, wounds 2.083 times, 0.694 times after saves and IWND will take that down to 0.139 wounds at the start of the next turn.
Guilliman Round 2 and thereafter: hits 3.333 times, wounds 2.778 times, 0.926 times after saves and IWND will take that down to 0.37 wounds at the start of the next turn.
A long as f**k fight, but Guilliman take the win 'cause Vulkan can't mathematically harm him.
Roboute Guilliman VS Lorgar
Lorgar hits 3 times, wounds 2.5 times, 0.75 times after saves and IWND will take that down to 0.417.
Guilliman Round 1: hits 2.778 times, wounds 1.85 times, 0.926 times after saves and IWND will take that down to 0.593 wounds at the start of the next turn.
Guilliman Round 2 and thereafter: hits 3.333 times, wounds 2.963 times, 1.48 times after saves and IWND will take that down to 1.15 wounds at the start of the next turn.
Even with forcing Guilliman to re-roll 5's and 6's for the first round Lorgar will still lose.
Note: this doesn't take into account Psychic Powers and with Precognition on Lorgar will win. On the other hand, Guilliman's rerollable DtW does have the potential to keep the fight's outcome up in the air.
Roboute Guilliman VS Perturabo
Perturabo Round 1: hits 2.667 times, wounds 2.222 times, 0.611 times after saves and IWND will take that down to 0.278.
Perturabo Round 2 and thereafter: hits 2 times, wounds 1.667 times, 0.333 times after saves and IWND will take that down to 0.
Guilliman Round 1/2: hits 2.5 times, wounds 2.222 times, 0.74 times after saves and IWND will take that down to 0.407 wounds at the start of the next turn.
Guilliman Round 3 and thereafter: hits 3.333 times, wounds 2.963 times, 0.988 times after saves and IWND will take that down to 0.654 wounds at the start of the next turn.
Again, Guilliman wins pretty safely. Starting to see a trend here.
Roboute Guilliman VS Alpharius
Alpharius hits 2.92 times and wounds 1.701 times (Remember he got Preferred Enemy), 0.35 wounds after saves and IWND will take that down to 0.017 wounds at the start of the next turn.
Guilliman Round 1: hits 2.5 times, wounds 2.222 times, 1.111 times after saves and IWND will take that down to 0.778 wounds at the start of the next turn.
Guilliman Round 2 and thereafter: hits 3.333 times, wounds 2.963 times, 1.482 times after saves and IWND will take that down to 1.148 wounds at the start of the next turn.
Guilliman wins really easily, as the damage Alpharius does is almost irrelevant, thus making the claim that he personally killed the lord of the Alpha Legion actually believable...
Roboute Guilliman VS Rogal Dorn
Dorn Round 1: hits 2.666 times, wounds 2 times, 0.5 wounds after saves and IWND will take that down to 0.167 wounds at the start of the next turn.
Dorn Round 2 and thereafter: hits 2 times, wounds 1.5 times, 0.25 wounds after saves and IWND will take that down to 0 wounds at the start of the next turn.
Guilliman Round 1/2: hits 2.5 times, wounds 2.222 times, 1.111 times after saves and IWND will take that down to 0.778 wounds at the start of the next turn.
Guilliman Round 3 and thereafter: hits 3.333 times, wounds 2.963 times, 1.482 times after saves and IWND will take that down to 1.148 wounds at the start of the next turn.
Guilliman easily win this fight taking less (Aka: None) damage and dishing out more.
Note: Dorn doesn't use Sundering Blow because he would actually cause less damage with it.
Roboute Guilliman VS Corvus Corax
Corvus hits 4 times (Scourge)/3 times (Shadow-walk), wounds 3 times (Scourge)/2.25 times (Shadow-walk), causing 1 wound (Scourge)/0.625 wounds (Shadow-walk) after saves and IWND will take that down to 0.667/0.292 wounds at the start of the next turn.
Guilliman Round 1: 2.5/1.666 times, wounds 2.0833/1.389 times, 1.389/0.926 wounds after saves and 1.055/0.593 wounds after IWND.
Guilliman Round 2 and thereafter: hits 3.333/2.5 times, wounds 2.963/2.083 times, 1.975/1.389 times after saves and IWND will take that down to 1.642/1.055 wounds at the start of the next turn.
Guilliman easily win this fight
Note: Like Curze, Corax could try to use Hit and Run to even the odds, having even more bonus than Curze thanks to his uber-Furious Charge, but unlike Curze it wouldn't work for too long as the second time they fight (whether Corax charges or Guilliman catches him) Guilliman will have him concussed (He's using his fist for a reason) for the rest of the fight and will kill him before Corax can escape again, thus making the strategy not viable against Papa Smurf.
TL;DR version: Surprisingly, despite being a more strategical kind of character and his generally not outstanding (for a Primarch) stats, Guilliman is actually a beast in 1 on 1 fights if they drag on long enough, turning the odds in the long run even against the most specialised Primarchs (in a really tactical way) and mathematically losing only to Horus.
So yes, Forge World has indeed made Papa Smurf 'King Shit'. That said, I personally like Guilliman, I just think it's a shame that power creep in 30k reared its ugly head with this Legion (in comparison to the other Legions already released, man, you gotta see a change here, look at Emperors Children, they aren't kicking Papa Smurf any time soon!)
~Macca