Barnett does, but he's done a lot of BJJ. And I don't think Saku did at all. His typical approach to the guard was to stomp or try to literally jump over it with punches.
From what I've seen, the pure Catch approach to dealing with guard is to leg lock against the open guard, and to just be happy against the closed guard because you're pinning the guy so he's losing. The fact that some of them have a better understanding of the guard I believe to be due more to cross pollination with BJJ, but one of the problems with Catch is that it's so rare there's no authority or real historical record to say what does and doesn't constitute a valid Catch technique. You can say 'oh yeah, there's an old Farmer Burns book where he shows a knee slice' but unless it's an emphasized part of the art I don't really count it. Most BJJ schools teach some takedowns, does that mean takedown proficiency is part of BJJ? I'd say it's (sadly) not, as evidenced by the fact that BJJ guys have for the most part shitty takedowns.
My general feeling is that judging any art by its practitioners in MMA is really hard, because anyone who is good at MMA is drawing from a lot of different traditions and coaches. The most you can say is that some technique from an art works in a real fight under a specific set of conditions. Which is not nothing, but it's not going to be an endorsement or dismissal of an entire art on its own. Only by looking at what works for a lot of people in a lot of fights at a high level do I think you can start to say that an art either does or doesn't work in MMA. Wrestling clearly does, BJJ clearly does, boxing, MT, they clearly do. Karate, Judo, and Catch I think we could say that having a limited sample size, they work for people who have trained them in a certain way.