This game concept sounds very interesting! I look forward to seeing where you take the MC. Swords and gryphons, hurrah.
On gambling: I have an optional gambling sequence in the fourth chapter of my current WiP, Beastie Watch, which is not randomised. It is based upon a game of brag, and is dependent both upon stats, and on the choices a player makes whilst playing. The hands are given, but your MC’s observations and options, and the bets of others, may change depending on your stats.
You’re more than welcome to have a look at my code, or I’m happy to PM you a link to the .txt file which contains that scene, if you like. The coding is (I think) fairly straightforward. I was writing the piece for CS Comp and only had one month; part of my goal was to make the apparent complexity of battles and card games loom larger than the actual complexity of the coding.
As to your broader question–I suppose it depends on your goals, and on how complex you want the game to be, aye? I like the idea of several diverse host (wielder?) options, but if it makes coding a terrible muddle then perhaps begin with a smaller field. On the other hand, basing results strictly upon combined stats seems to be simpler, at least from a coding perspective.
I hope that’s helpful!