Not sure how you define "appreciably worse" but two of the possible comparators can at least say they were top 100. Although Naomi would, I expect have been getting as good training at Mourataglou as she would have done anywhere else. So I agree she's probably no worse off other than financially.

I think the natural flaws in her game have never been given sufficient treatment, why I dont know, maybe it was easier to try and make her strengths stronger. If she'd sorted some of the bigger technical hitches (particularly on her backhand) years ago she'd be a bigger achiever I think. Still time, but more likely I think to only make the best of what she has got now, which I would question whether is top 100 material.