This is an amazing late-game card for Cage, particularly in Protection (with Toughen Ups boosting the Tough card count). Once you are regularly stacking several toughs, you get to be super-selective about the cards you play, since Cage in Hero has no SCH -or- ATK pressure. Making it easy to play this card twice a turn. Then there is the added benefit that stripping a tough does a single damage to Cage, allowing him to recover and abuse Toughen Up for more Toughs. (again assuming the Protection aspect.)
In any other aspect, you will still be able to make use of this card in the late game, but you'll lean into the hero deck cards a little harder. This is essentially Clobber with a highly unique recursion that ends up giving Cage some offensive chops outside of Aggression.
I think I would happily have lost a Harlem's Hero for another Knuckle Sandwich, but that's only because I haven't even thought about Leadership for Cage yet. He is the Rock of Gibraltar in Protection and I am all about it right now.