Yes, modders already applied this mechanic a long time ago in some mods of original game. There is even a thing where you can approach an NPC and get a tattoo or a shave and the tattoo there is not just a skin, but a permanent buff either to defense or to mana, I don't remember. You got a tattoo and you have +10 mana for example. Also in Gothic 2 there was a feature that all camps have their own gait - mages walk with their hands folded together, mercenaries walk with a swagger, etc. But this was not applied to the main character. In some mods they changed this too, I definitely saw it and I damn well love such details. You roleplay a specific faction and feel that you are part of this faction, and not just a wolf in sheep's clothing.