i would think that IC's and MK would work:
1.IC's hav amazing grab combos that could turn into kill of combos from MK
2.I'm sure they could both hold off on their own if they get seperated.
3.People use initials to define them XD
But then again I could see Bowser and MK, MK stays in back behind bowser, when the oponents come up bowser hold them off, then metaknight comes in then **** them both, after raking enough damage, have Bowser finish them. I gues that wouldn't work for all of the char's though