The problem is not that these tag teams are OP, but rather the fact that this is the sign of a ridicolous power creep that is to come in the future - I mean, three prizes for 1 KO? That's half of your prizes right there. And who knows, this might just be one of the worse tag team cards.
Plus it's not exactly a very imaginative idea either as far as new game mechanics are concerned.
It depends on how long TPCi wants this to hold out. The LEGEND cards they were based on lasted a short time and they only have a handful of cards, hardly enough for every deck to find something it could use.