Holy Christ....

This is a fantasy game. The REALITIES of human biology between Men and Women are 100% irrelevant in the game world. The REALITIES in the difference between Fast and Slow Twitch muscles are also, irrelevant.

This is a fantasy game, where monsters need slaying, people need saving, and spells need casting.

Why are there different appearance between the same gear?

Same reason we had it in WoW. Same reason we see it in Japanese RPG. Same reason we see it in Fantasy art going back decades to the formative era for what became 'fantasy art'.

Petition for options? Ask for a way to modify? ABSOLUTELY.

But I can tell there are some intelligent people here dancing around the reality of the WHY when it's not particularly relevant.

And no, the historical accuracy of women fighting during the Roman Empire era, is not relevant to the creation of Bikini Chain Mail, or Conan fighting in a Banana Hammock.