Would Schmeling have been the hardest puncher Marciano faced?

He couldn't. Out of the 6 opponents he faced between the Charles and Marciano fights, he knocked out Savold and he stopped Beshore and Walker on cuts.
Brion, Agramonte and Bivins all went the distance. In other words he failed to knock out half the people he beat.
When he went pro in 1934 to 1948 when he first retired he fought 50 people. He knocked out 46 of them. Only 4 men escaped being knocked out:
Kranz
Wiater
Perroni
Farr

Not a single person managed to last the distance in a rematch.
Both the men he rematched in his comeback went the distance.

In other words, in just the one year of his comeback, he failed to knock out about as many people as he did in the 15 years of his first career.

Perhaps power is the last thing to go. After he lost his reflexes, stamina, handspeed and coordination, he also lost his power. But to say 1951 Louis was as powerful as pre retirement Louis is a ridiculous statement.

Johnny Risko was knocked out twice in 119 fights. The last knockout he received in his last fight against Tony Musto after a 16 year career. The other knockout he received in his prime.
Young Stribling was knocked out once in his 251 fights.
Those two knockouts were delivered by Max.

1951 Louis does not hit half as hard as Max Schmeling.

 

If im not mistaken Schmeling is ranked somewhere around the mid 50's as the hardest punchers of all time.
I have to go with Louis on this one and its not even close.

 

Louis was shot and had little but his jab. Walcott then Moore

 

strong post

 

I’m not sure. Schmeling could certainly crack but I’m wondering if for him it was more about precision rather than just raw power. Archie Moore had a lot of power even at heavyweight as did Joe Walcott.

 

Schmeling was a sharp shooter with a good, jolting right hand that produced power with his good timing and accuracy. He was a natural counter puncher who'd use the opponents momentum and defensive holes against them.

That being said, no, Schmeling would not be the hardest hitter Rocky faced in terms of raw 1 punch power. I'm fairly certain Archie Moore, the KO King of the light heavy division, hit at least slightly harder than Schmeling who was a fairly small cruiser by modern standards. Moore has both the record and the footage to prove he had more raw power. I suspect Walcott's left hook delivered more raw power than Schmeling's right hand due to the speed and awkward angle.

 

It’s hard to knock people out when your speed and reflexes go but Joe still carried power he last great performance was the rematch against Walcott, whether Max hit harder than a 1951 Louis is hard to determine but the key point is wax Schmeling a top tier power puncher compared to other ATG’s and the answer is no I doubt he even makes the top ten

 

It's not hard to determine, he looks weak on film when he does throw his right and can't twist his body into his punches like he could before. The punches themselves do not have the effect on people they used to.
The Walcott knockout was before his two year retirement. His last performance was him being beaten by Ezzard Charles in his first comeback fight.
I posted a video of max putting the European champ to sleep in 70 seconds. Do you think 1951 Louis could do that?
Max no longer makes the top ten punchers list probably but until 1960 at the end of Rocky's era he most definitely would.

 

Louis had no right hand. Had to be the blown up lightheavy Moore.

 

I think the point still remains even if Max Schmeling wouldn't have been the hardest puncher Marciano faced, at worst he is 3rd behind Walcott and old Joe Louis. It speaks to the level of competition Louis, Charles, and Walcott all fought relative to Marciano. Patterson's dubious title run aside, he also fought tougher men. So historically speaking, the champs immediately before and after Marciano fought tougher fights against harder punchers.

 

Its Debatable. In terms of raw punching power Jersey Joe Walcott, Rex Layne, and Bill Wilson were hard punchers. Ezzard Charles and Archie Moore also weren't exactly soft punchers and could punch hard when they needed to.