Well, it seems that I'll have to parent the objects to the joint. I was not expecting to do that, I really wanted to do the thing organized. I've seen many fnaf robots rigged without mixing meshes and all that stuff. Anyways, I don't have choice, at least for now.
Also: Thank you for the advice! I think you're right with the "bolee". Like, I'm really lazy to work with polygons, literally I had to model an endo skeleton under the suit, and I said "Nah, let's just finish the model, I'm tired and I want to sleep". So, I added that ugly bolee, and I'm aware from that. That being said, thank you for the advice about the bolee, I should make things cleaner.
Thank you for the help and the feedback!