Cringejudo being Cringejudo.
He would dominate. He’s not really all that much smaller, Nunez fights at 135 and 145, though she’s arguably undersized at 145 (doesn’t matter, because it’s a thin division and she already blasted Cyborg). Henry is shorter, but he’s fighting at 125 and 135 now, and he cuts a lot of weight to make 125. Earlier in his career, he missed weight a few times. Even at 135, he’s probably cutting at least 10 pounds or so. So size difference isn’t that big. Henry’s also not just a man, but an Olympic gold medalist and an amateur boxing champion. Nunes just isn’t going to be able to overcome the strength and power disadvantage. Henry is also better technically.
As was said above, it’s going to be very hard for even an elite WMMA fighter to beat any UFC-level male fighter. The physical discrepancies are huge. I’ve said this before, but back when I did Muay Thai, I sparred with a multiple-time female Thai champion who was doing a seminar at our gym. I’d been training maybe a year and a half at that point. I would just run her right over. She’d hit me with shots, but I was so much bigger and stronger, I could pretty much walk right through them. She was most certainly a better fighter than me and her technique was fantastic, but I was literally 3 times here size or bigger. Technique helps overcome power, but not when the discrepancy is that big. Granted, in this case, Henry’s probably about the same size, but it’s all about the strength and power advantage.