At the moment, I would say all. Manually canceling units from garrisoning should be easier than manually adding units to a garrison, and I don't trust simple heuristics to micromanage my game for me, anyway. On a different tangent, I think it's also more mod-friendly if it's not hard-coded to distinguish female workers from other workers (soft-coding is fine provided the modders can easily change it). For example, mods with only one type of workers or mods where female workers are more proficient in combat.