Indeed. Off the top of my head there's 5 high level wrestlers who are currently in the UFC (Zingano, Vieira, McMann, Suarez, and Esparza), 3 of them have either fought for the title or held it and the others are ranked in the top 3. Then you have Tate who was a former title holder and recently retired along with Claudia who was the perennial #2 for ages. Every decent wrestler in the UFC has done just fine on the women's side, and I'd argue that they've had even more success than the men.
IMO truly 'high level wrestlers' in WMMA, that I'm aware of, are Suarez, Kanako Murata, maybe Lilya Shakirova. None of them have had difficulty implementing their wrestling.
(I guess depending how high we spread the term 'high level' yea all those others Vieira Zingano etc count... they all do fine as you said)
As far as the collegate ones go, there is no comparison with the UFC's crowd of 'murican male collegate wrestlers, there is a huge system for collegate wrestling in the USA which gives that country the biggest pool of (male) wrestlers anywhere in the world. Those people now have a post-college career path if they want to continue to be about dat jock life, in MMA.
That's not the case for women, and it is especially not the case for women 10+ years ago when someone like Ashley Evans-Smith 'all americaned' in female collegate wrestling, a tiny sport with a tiny pool of competitors from 1 country. To tell if they are 'world class' or not, I'd want to know how they competed internationally, which is the real test for determining how good a woman's wrestling is since Freestyle is the main focus of the women's side of the sport (because the Olympics); not collegate which is its own world.
So it's no surprise if the skill of an 'all american' female collegate wrestler with no international record from 10+ years ago is highly variable. They may decent (Esparza, Cat, Miesha) or ..... well, maybe AES was better in the sport of wrestling than at MMA wrestling? I dunno....
Maybe that's true to some extent for men as well (I mean, it is 'world class', not 'USA class'...) but since there are so many more male collegate wrestlers, there are plenty of really good ones who don't make the world team because their are just too many beasts in front of them (plus, no money). Not being american I don't really know what 'all american in wrestling' means as a measure of skill though... but I do know that
a girl all-americaned in Greco Roman wrestling last year, which is absolutely hilarious to me (not least because there is no such thing as 'women's greco-roman'). The number of female collegate wrestlers has also increased considerably over the last decade though (I think it's up like 250% or thereabouts since 2012) and the USA has a growing pool of good women wrestlers (a lot of whom express an interest in doing MMA in the future, now that the option is there).