I think, though, that a huge amount of Miles' personality developed *in response to* Barrayar. I suspect that if he'd grown up Betan, he might still have developed that charm (remember, it was developed early as a way of getting others to do what he wanted because he couldn't physically do it himself) but I think a lot of that "I'll show you I can do it anyway" would be missing, and he'd be a vastly different person without that. What do you think would happen?