I understand where you're coming from, but I feel like your post is a bit misleading. The exos were never human. The exo body was created "for a war long forgotten". It wasn't until afterwards that (and I'm assuming a small but here) human minds were implemented into the exo bodies. Also, while you are more than likely correct, there is no real indication that the name exos were implemented with make brains as we do not know the process by which the exos were infused with light.