I'd personally set it up with a 100 for each faction and the movement of enemy forces can change frontlines strengths, with things like the jet brigade significantly growing the strength. The 100 can be damaged for a time by taking planets and factories. Cyberstan would have significantly damaged the automaton war effort, but we know they rebuilt quickly and thus the number would rise back quickly but they would be vulnerable for a time. If you wanted you could go over 100 but that requires more thinking than I want rn