That's not how that fight worked at all. The 11 hours was the start to the end, there wasn't 11 hours of G4 fighting. Luffy wasn't even in G4 much of the fight according to Cracker's explanation, "You run you eat you fight" The majority of the fight was Luffy eating biscuits. And unless Oda expands on the fight it only took one "hit" from a G4 "attack" which can't really even be compared to KKG seeing as it was a launching/cannonball style attack and the damage came primarily from the objects Cracker crashed into, all G4 did was throw him with ridiculous force.What does Cracker's real body have to do with it. That is not even up for discussion.
According to your definition Cracker 'tanked' 11 hours of Luffy and Doffy only 40 minutes. This is not a hard body contest it's a fight and you keep taking Crackers ability away in order to make him look weaker.
You can't say he was 1 hit knocked down because it took 11 hours and hundreds of hits.