A piece of steel to protect the chest used to be pretty expensive, as well as well made weapons. So, if you consider this fact, it would be pretty common both lowborn male and female warriors and adventurers to have a few parts of armor to protect themselves, while a noble and rich people would be able to afford a full plate armor. Also, armors are made of many diferent layers of diferent materials.
This is a fantasy game, but that concept would explain the "bikini armors"...
maybe, if characters could have an extra slot to equip clothes of diferent kinds that would show beneth the armor... so you could have cloth and chainmails under the armor or take it out to show the female character's atributes.
A good example of that idea is Neverwinter (online). I don't know if its something easy and viable to make, but surely would please both publics.
