The problem with this is that dexterity beyond a certain level is very specific to what has been trained.

I have a friend who is an eye surgeon. I'm definitely better at playing guitar and piano than him, probably equal at things like juggling and card tricks, but absolutely inferior when it comes to cutting people's eyeballs apart.

It doesn't invalidate your point completely, but just because someone is good at plaiting hair doesn't mean they'll be good at surgery!