According to the information given, they all have the same recoil. The Mauser C96 was initially made in I think 7.63mm Mauser or something like that, which is actually a fair bit weaker than 7.62 Tokarev which is 7.62x25 which is almost identical (or actually identical) in the 7.63 Mauser’s dimensions. Regardless, if we’re to assume that the C96 are 9mm (like the Red 9 of WWI) just like the Luger P08 and the Walther P38, then they should indeed probably do the same amount of damage, BUT, the C96 has a HIGH bore axis. This means that, in accordance to the position of the hand, the bore is quite high, which causes more ‘muzzle flip.’ The C96, the first pistol accessible for the Germans of the Moscow Campaign, should have the most recoil when compared to the Luger or the P38 Walther. NOT because it’s the oldest of the lot, or the first accessible of any German pistols on that campaign, but because of its DESIGN. As for Luger vs Walther pistols, I don’t know, but the C96 should be the worst-handling of them all unless it has its shoulder stock holster applied thus rendering the pistol to be a short-barreled carbine.
So yeah, either the C96 recoil should be made worse (which would suck) or the P08/P38 recoil should be eased, assuming all three indeed have the same recoil impulse and muzzle flip, which they shouldn’t, in spite of all potentially firing the same cartridge.