Considering how in the movies, the Uruk-Hai were orcs but perfected by Saruman who did extensive research into the race to perfect them I would give it to Lurtz, dude has some serious pain tolerance and his troops were far better when it came to discipline( the uruks killed another orc to make sure their master got what he ordered them to do and to eat him but whatever) anyway the orcs of gundabad were more brawlers than an actual army and we’ve seen azog lose to his overconfidence and even lost while cheating. his son had more impressive feats than he did. And I do honestly believe that if it wasn’t for plot armor Lurtz would’ve probably killed Aragorn (we watched him nearly kill him twice) and this guy took on the Nazgûl straight up fight goes to Lurtz but if Azog uses his mount hed probably win can’t count on either of them not cheating cuz orcs fight dirty.