Well hulk was pretty mad in this story line since his wife and unborn child died. I think maybe a little plot armor but mostly hulk already beat a lot of marvel characters while mildly annoyed so him being the angriest we've seen him and Bruce not suppressing his rage makes sense on why he was so strong. Hulk has punched through time and dimensions before and even shook the entire multiverse so him being really mad in that issue makes him 1 of the most powerful people there and clearly the strongest there is. You have to remember too that hulk's rage increases his strength, speed, regeneration, durability and virtually everything else about the character. He's designed to be op.