There's a lot of Capcom characters who deserve to join, but the more Capcom characters are in one Smash game, the more money Nintendo would have to pay Capcom and they can only spend so much on so many 3rd parties in one Smash game. Let's assume the budget is no more than 3 3rd parties per company in one Smash game. Mega Man, Ryu and Ken are in Ultimate, but what if we replace them with Dante, Leon and Monster Hunter in Smash 6, but in Smash 7, we cut them and put Mega Man, Ryu and Ken back in, then in Smash 8 we cut them and put Dante, Leon and Monster Hunter back in and in Smash 9 we cut them and put Mega Man, Ryu and Ken back in and the cycle would keep going on and on. They'd take turns being in Smash games, and also sometimes we could get 2 characters from one trio and one character from the other trio.