Actually we're arguing that the important number is who can deliver the most damage on target in a match rather than who can hit a non-defending stationary target harder.
In terms of actual power transmitted to a punch my bet would be on an Olympic level shotputter, just based on sports science (its the most powerful non-mechanical motion that's been measured in sports). Of course they're all freaky strong 300+ pounds (ie they don't need to worry about stamina at all so can work on pure power) and jump into it, so they'd never land the punch in the ring or cage and would gas out in far less than a minute if they fought, but if its just about power delivered against a non-defending stationary target I'd happily bet they beat Fury, Ngannou, Wilder and anyone else and probably by a considerable margin. For that matter, I suspect someone like Brian Shaw beats actual fighters too.
The important number for a fighter is how hard they can land on target in a fight.