I don't think the Watson to RG3 comparison is valid. RG3 either never learned or wanted to protect himself, he intentionally took hits, lot's of hits, many very avoidable. He broke down over time because he failed to protect himself. The polar opposite of RG3 when it comes to avoiding hits is Russell Wilson he is a magician, stepping out or sliding (yes I know he takes hits, because it's football, no gif's showing exceptions please). Cam Newton is doing some RG3 shit, but he's bigger and will take longer to break down, but it will happen if he doesn't change.
Watson and Trubisky both fall much closer to the Russell Wilson style of not getting killed. Watson got hurt, but in a non contact practice, I'm not saying that's good, but it has nothing to do with what happened to RG3. Trubisky either already knew or has learned how to protect himself and so far seems to be durable, point Mitch.
Will Watson be Mr. Glass that can't stay on the field, we will find out. Because of his obvious talent he will be given every chance in the world.
Does Trubisky have the talent to succeed, we will find out. Because of the draft investment he will be given every chance in the world.
I wish them both well, the NFL needs all the great QB's it can get, also Trubisky because he's a Bear, and Watson because he's not in the NFCN.