He is not talking about any specific value of DPS, but it's easier/different to balance out squads which have all the same type of weapon rather than ones which focus the damage in few models while the rest of the squad has weapons with a completely different damage profile.
Ex:
-LMG + Bolt action is fine because you want to engage at long distance and mostly static.
-Carbine + Bolt not so much. You rely on the Carbine doing the heavy lifting, therefore it having better stats individually.
It's shifting the power budget of the upgrade from an offensive standpoint to defensive values (1 extra man and constant DPS).
Ohhhhh...... Thanks that was a nice explanation.
I wish the mod team would work on this, the g43's storms are not work getting over the pg ones or eve their own mp40's.