Done right, gender imbalance would be good in an RP.

On average, women have a harder time becoming quite as good as men for say, combat. The average woman is, undeniably, somewhat less physically strong than the average man. But this does not mean its impossible. We love stories where there's female characters that are strong in various ways.

If men and women are exposed to the exact same physical strength requirements, fewer women will pass through than men. But when it comes to mental strength, its much harder to say, if not impossible.

When it comes to fantasy RP settings, we can say this:
We hate the concept of Chainmail bikini armor. 

We don't mind if there's female (or male) warriors who are dressed in loincloths. Its not good defense, but it can be explained away. Chainmail bikini on the other hand, that shows they have the skill to make metal armor, yet choose to make armor that doesn't cover what armor ought to cover. That, is unforgivable in a character. They only deserve to be killed if they do that.
On the other hand, we don't mind it if a writer wants the armor to be "feminine", so long as it does not compromise its capability to offer protection. As such, while breasts on armor would look feminine, there should not be any cleft in between them. All that would allow, is a path for unfriendly weapons to slide directly in towards a vulnerable spot, rather than out and away from the chest. If a suit of armor should have "boobs", it should be a single bulge for both, so that anything striking that point will slide out and away. If you want to accentuate them as more separate, there is always enameling and such.

Mind you, in settings that aren't quite so focused on bladed weaponry, armor requirements are less strict on this front.