You can wear dresses as a male on battle/siege servers if someone builds a weapon rack and you change your equipped body armor to a dress mid round. I don't see why this wouldn't work in strategus as well, but no one ever brings dresses in their army's equipment so I can't say.
You probably shouldn't do this, at least not on the battle server. Weapon racks are rarely used to a team's advantage and people will report you for leeching or trolling your team.