Peak popularity of the Outlawz>>> Hart Foundation by a mile, shyt isn't even close
Was the OP strictly talking popularity though?
Also if you really break it down, are the outlaws really popular for their WRESTLING or their antics. I remember promos, skits, parodies... but I don't remember them having many classic battles against other all time great tag teams.
Hart foundation thrived in an era of nothing but GOAT tag teams. Bret himself was so good he was able to be an all time great singles competitor.
What did road dogg and billy gunn ever accomplish without each other and without DX?
Just food for thought.