They announced last night that they are adding balance changes to hela and Hawkeye (that's on top of them losing seasonal bonuses) and buffing lower end heroes. And I believe they are going to keep balances in the middle of a season to a minimum. They plan on beginning, mid and possibly end of season balances.
And marvel rivals still needs to create characters from scratch, make sure their abilities make sense for the game, that the models make sense for the character but also fit with the flow of the game. Which iteration of the character you want etc. Yeah there is already an existing pool, but blizzard also has a pool they can work from too, it's the fact that the OW universe limits it since it's completely based on tech and limited to a foundation and that means to keep characters unique from each other much harder. Marvel allows for magic for things that could be beyond scientific thoughts
