got off-paneled by both Iron Fist and Luke Cage on different occasions
Which occasions are you talking about? I remember a fight where Iron Fist easily punched Colossus through a wall, but that didn't KO him, from what I remember. Also, when did the Thing fight Strong Guy?
Iron Fist off-paneled Colossus in Contest of Champions II #3 (should be noted that the book had a lot of dumb outcomes, like Black Widow beating Wonder Man and soloing New Mutants, or Black Panther soloing New Warriors, or Storm beating Human Torch):
Luke Cage off-paneled Colossus in AXIS #9:
Ben fought Strong Guy in X-Factor #200 (in a short fight that had Strong Guy quickly beaten and needing to be saved by Shatterstar of all people) and in X-Factor #201, in even shorter "fight" that consisted of SG tackling Thing and then getting casually tossed aside like garbage.