His friend may be hitting the attack soft cap — that would explain why the damage for the one team is as expected, and the other is lower.
@ThePirateKing @Gryphonknight as far as I know, we collectively know that an attack soft cap exists, but don’t have a formula that incorporates it into the damage calculation, due to a lack of knowledge of exactly how it works. Do you know otherwise?
I know @Garanwyn was onto a solution for it when he dropped out of the game, but he didn’t finalize and publish it before he went on hiatus.
Also linking this for cross reference: [Research] Does Color Stacking have a soft cap? or Attack stat research