[Squirrelloid]

I think there's a big mistake being made here - you're talking about 'equal' combats.

Best way to not lose: never fight an equal combat. Seriously. Baalz's tricks can make a particular combat more asymmetric in your favor, minimizing your losses. Any discussion which starts from 'assume equal investment' is inherently flawed.

Now, since we're talking about not-losing, we're probably also talking about fighting defensively, which means you can probably ensure you bring the biggest army to the table because you're closest to your center of production. You're also under threat, meaning the marginal value of using mages for research is lower relative to value of using them in combat (can be returned to research faster, threat to your existence makes not winning relatively more costly)