Both hit hard enough to put the other out. Truth is DC isn't looking to finish fights via 1 kill shot punch. If it happens, like when he fought Big Foot, then he accepts it but he's not looking for it. He's a grinder and WANTS to make the fight ugly.
Stipe is always looking to knock someone out. That's his battle plan. When he can't knock someone out then he doesn't have a backup plan except keep punching. In his fights against both Hunt and Ngannou by the 4th round, both his opponents could have been finished with a TD and a sub. (especially the Hunt fight. Hunt was done after the second. Between the ref and Hunt's corner all should be ashamed for letting that snuff film go on). In both fights, Stipe was content to lay on the other dead tired, gassed out guy and keep punching.
The question for this fight isn't can DC take Stipe's punch. (Which he can. Rumble definitely rehydrated to +225 pounds and hits harder than Stipe) The question is can Stipe stop DC from ragdolling him?