So, supervillain team-ups: yay or nay?
Diabolical in Manhattan
Short Answer: Absolutely, if you want the heroes to win.
Long Answer: Realistically, partnerships require “good guy” character qualities to be sustainable in any way. In the absence of a virtuous purpose to transcend more petty motives, one or both of the partners involved will be planning to end the alliance treacherously from the outset. The only force more capable of destroying a super-villain than a super-hero is another super-villain. If the forces of good could trust them, they’d hire super-villains and fire super-heroes. However, they can’t trust them and neither can you.