Welcome to the swamp, hope you survive the experience!
Average model count for the game as a whole is 6-9, Bayou run on the higher end since a lot of the smaller models cost way less; Big Hat is A LOT of smaller models so they're gonna run probably 9-12 models plus So'mer keeps summoning more. I wouldn't recommend starting with them, but it's what they call "high entry level" skill wise: You don't get the hang of how it works for a while.... but once it clicks you'll be neigh unstoppable.
Infamous is very easy to learn, but has a lot of moving parts. You'll pick it up quick, you'll start winning quicker, but it's gonna take 10-15 games before you realize how all the little things synergize and then you shift into a whole new gear and also become neigh unstoppable.
Long story short: start with any faction, any keyword, any crew, work at it, and eventually you will be neigh unstoppable!