I like modern(-inspired) militarized settings because the variation of outfits and excuses to wear them it offers the ladies. Sure, your medieval setting may have the rough-on-the edges musclegirl, but there's not a lot of variation in what she can wear. Can she start the day waking up in a nightgown, dress like an office lady for paperwork, switch to fatigues for field work, wear your dress shirt when sleeping over at your place, switch to her dress uniform for the victory parade and then wear a sexy dress to take you clubbing to celebrate - all within 48 hours?

Face it, modern and hypothetical future settings are unmatched due to clothing variation.