I've watched their first fight back a few times now and I don't think Kai landed anything that actually hurt Moreno. I know the commentary team stated Kai hurt Moreno during the first round but if you slow the sequence down none of the punches appeared to land clean and most didn't land at all. I believe it was more-so bad body language from Moreno than being hurt.
The Norman fight is an amateur fight and while its fine to watch those to gauge the skillset of fighters they shouldn't be taken as indicative of how a fighter will perform during professional bouts.
Hamdy nearly went three full rounds with Dustin Clements, an experienced fighter, in his professional debut. Thats a good fight to watch if you want to gauge Hamdy's current skillset rather than him bulldozing winless opponents in his other 2 bouts.
I don't think you are wrong though in taking away from Hamdy's fights that he is used to imposing himself on smaller opponents and winning through sheer physicality. That likely isn't going to be an option against an opponent who is quite a bit bigger than him.
Hamdy may have weighed in 9.5 pounds heavier than Mayes but that is excess weight (fat) and not going to help him. Mayes is too big and strong to be kept down by anything other than superior technique.
She got robbed, according to some, in her last fight against Cachoeira. Kim is likely going to throw a ton of volume and headhunt, as she usually does, but there doesn't seem to be power in anything she throws and competent judges will take notice of this.
Edwards appears to hit quite hard, I have heard her previous opponents say this in interviews, so I don't foresee the volume of Kim alone being enough.