I have a fantasy world with roughly medieval technology (swords, crossbows, and chain mail for instance), and I have an egalitarian country with an army that's somewhere from 10 to 40% women (it probably varies over time). 

It is a fantasy world, so some people do have magic, which is equal among genders. However, I'd imagine that most people with skill or training in magic would be in special units.

Based on this, what should I think about when I'm formatting the structure of this country's army and military life?