Question How can the animation rig be simplified?

I wanted to simplify the model for optimization, reduced the detail to reduce polygons, but this did not work, the reason was precisely in the animation rig, I simplified it a bit, removed all the fingers in rig, this really had a positive effect on performance, then I tried to remove more others bones, but then I can no longer apply the humanoid rig type, it writes an error that there is no one or another bone, and in fact 5 bones would be enough for me to make the model visually look normal, we are talking, of course, about a low-poly model that will be displayed on the far distance.
The question is - how can the animation rig be simplified?
Is it possible to leave 5 bones (arms, legs, body) but still have the animation applied?
Tell me what can be done in this situation?

(for some reasons without applying animation-to-texture baking)