just want to put my suggestions out there
1) make 2 factions, the first one is a group of skeletons who just wants to survive the harsh rimworld (good faction), the second one will be a group of skeleton who want to do nothing more than see organics suffer (Bad Faction)
2) instead of waiting for a skeleton to walk by, why scoop out the AI core of dead skeletons and put them into a new body, and give them a temporary mood Buffs and immediately allied to your faction (say you wiped it's memory)

and i kinda like a Machine uprising stories