Its like comparing Adonis' power with Kov's. I think both have equal power, Wilder just uses less punch output and relies on timing instead like Adonis.
AJ has shown his power is effective against top tier opposition. Wilder went the distance with stiverne, barely putting a dent in him. The molina fight is a good barometer.
Took Wilder 9 rounds to take out Molina he hit him with a lot of hard shots and Molina kept on getting back up. Joshua took him out in 3, landed one clean right that dropped him and was defenseless after that. Maybe Joshua has better delivery and better finishing skills, but that combined with greater weight, I say Joshua hits harder.
Wilder has that whip like power that comes from long limbs and explosive speed. He also throws with full power almost every time he sees an opening so gets the maximum from the shot if it lands. Joshua's power comes from his strong core, solid foundations and good technique. He rarely throws one big shot out of left field but prefers to throw three or four hard compact shots then return to a defensively sound position afterwards. Due to the way Wilder throws (like a baseball pitcher) even if he lands the first shots he's got too much momentum to follow it up with a second or third, and his poor technique means he often ends up flapping away with slaps that come in from too wide and risk damaging his hands. Essentially, if someone gets hit with a full extension Wilder right hand they're likely not getting up. If they get stunned by a Joshua shot there's likely two or three more similarly hard shots coming straight after, resulting in the same scenario. Joshua's more dangerous as a result, since it's easier to avoid a wild telegraphed punch from the outside than it is multiple short stunning shots thrown behind a compact and dangerous jab.
AJ without a doubt. Wilder is total trash. smoke and mirrors. I'd knock him out. Couldn't even get rid of that fat bum Stiverne. Imagine what Joshua would do to Stiverne?