I used to have a problem with Mei, Mabui, GNW Tenten teams, but then I got Roshi + utakata.

I haven't lost to them yet. The immunity from Roshi helps a lot. Mei, Mabui, GNW Tenten, is set up to burst you down. After turn 2, they can't do anything to you and their burst is dead. They have to kill 2-3 of your ninjas before Round 3, otherwise they will just slowly lose.