Not sure this is necessary at all. If biomass is capped at 150 per UE or 125 per UE, the half as effective biomass on the rest of the army is already a self-limiting nerf. Essentially the player runs either:
- Same few UE with army that are “less than 1/2 biomass effective” (as the later bonuses give bigger break points).
- Run more UE by focusing biomass onto each individual army.
Either one of these options would give you no issues in terms of the supply cap. As option 1, even with the same supply 200/200 (but only 3/3 UE), would work half as effective. And option 2, the amount of biomass to even reach 100 (or 50ish army supply… or about 25 roaches) is 25 x 125 (or 150) biomass = 3125 (or 3750) biomass total. That’s a lot for just 100 supply, to reach 200 supply capped would triple this number into 9375 (or 11,250) biomass.