@GattlingCombo Pretty much. When dealing with a fight you're not just focusing on one other combatant, but also their team mates, and your team mates current predicaments. When you throw an even somewhat competent Maeve into the mix everyone has to adjust what they're doing just because she is present. And at any time she can merely cage someone, vanish, go get some health, and be back doing it all over again in 15 - 20 seconds. She is the epitome of an overpowered character in a game like this.
Buttercup is only slightly worse because even though she can quickly dominate and kill anyone trying to defend or attack a point, at least with a little communication she can be burned down. But given all of the tools at her disposal she still does far too much damage. And that Mortal Kombat Scorpion skill has far too much reach, which makes her even worse. She can grapple people into her group that couldn't even attack her from range if they spent several more seconds closing in.
The two characters have glaring issues everyone can see. So just fix them. It isn't hard. It's not like this is the first arena combat game to have had challenges with a few characters. It's just that with Bleeding Edge they don't seem to care.