I am not sure that whether this topic is discussed before or not?
I found that Peggy blue power is good
I only have Peggy blue so I want to send her as team-up
However, it is not allowed
My alliance sent me Peggy team-up
There are all Peggy red power
I don’t realized why Peggy blue could not be used as team up???
I would guess it’s because of the “places one 3-turn Blue countdown tile for each active ally” part. Ordinarily you’d get three tiles; if it was used as a team-up you’d expect to have four, as the last one is Peggy herself (with animation). This would make the team-up more powerful than the ability as used by Peggy.
Righteous Uppercut doesn’t count Cage as an ally when you have him in your team. This power is stronger when you send it as a TU (bonus damage x3 instead of x2)