Ok!
It's the
Recruitable Unit Rebalance that I just finished and finished documenting yesterday. It mods almost all combat units (e.g., not mages) that you can recruit without magic, to make them more balanced, more fun, more interesting, and make useless units more useful. It does not affect scales, pretenders, or magic spells, so it is perfectly compatible with mods that alter those things (like Zen's balance series).
Well, I don't want to apply any pressure, since I'm not playing. But I'd love to know how the mod feels in MP!