Playing Boxing Manager on iOS, realised one thing WMMA has lacked is a meaningful fighter happiness model
If a fighter signs for a company on a 5-fight, 2 year deal for example, but only fights once in that time, they shouldn't be happy and shouldn't resign when the 2-years is up: currently the game is set up so that if the company wants to sign the fighter, they resign regardless (AI or player-controlled).
If there is any further development with the franchise, this would be a major addition to the game
Similarly the unhappiness with the booking some fighters report should have consequences - I've never had a fighter refuse to sign/resign because they were unhappy (although it may be that I release fighters on three Ls in a row, which is why I've separated from the main point above)