General approach to character model with "FPS" arms

I’m creating a humanoid model for a FPS game. This includes a full character model for cutscenes, where you see the whole model, as well as separate arms/hands that are shown from a first-person perspective. Basically, almost every FPS game ever has the players hands extended forward from the bottom of the screen. Those should be a separate model, since the player shouldn’t see their whole body, just the arms/hands.

My general approach on this is that I’ll create the full character, but keep the arms/hands as separate meshes. I’ll rig the whole thing. But when I export it, I can either export all the meshed for the full character, or just export the “arms/hands” meshes for the separate hands. I’ll still include the full armature for the separate “arms/hands”, so that normal animations can easily be used. Does that sound reasonable?

The complex thing about this is that I want higher detail for the separate “arms/hands” mesh, but only when they’re exported separately. When the arms/hands are included in the full character model, they should be less detailed, consistent with the rest of the model. Is there an easy way to manage this? I don’t want to have two copies of the arms/hands, since that sounds like a ton of work to maintain. My thought on this was that I could model the entire character at the same level of detail that I want the gloves at, then somehow lower the resolution of the model when I’m exporting the full character? Does that seem reasonable? Is there a simple way to do that?