I would consider Grapettes-Guevara to be in the top half of that group you listed and I think Nevada Stealth and Mizuno-Morabito belong on the list. Stealth has 2 pitchers who can really bring it. I watched Morabito vs Breeze 02 on Sat and the team looked very solid to me.
I know lots of teams in the 20 can beat almost any other team on the list depending on the day, so that should make for some entertaining head-to-head matchups on Sundays this spring. Right now, though, I'm just focused on getting ready for Vegas.