Max Baer had over 50 knockouts, including Heavyweight World Champions, Primo Carnera and Max Schmeling. And his technique was not all that conventional. I'd say that indicates that he was a very powerful puncher.
A fighter who can do it all at the highest level, on power and reflexes alone, is a very rare creature indeed. Examples include Baer, young Foreman, and more recently Wilder. Baer's power is the one thing about him that nobody should question, because it was the key to everything.
If he can kill people in the ring, then he is very powerful. What Max Baer did to Carnero is savagery.
He even got the body, Frankie Campbell (RIP), on his resume that Wilder professed to wanting so badly but never got. It was terrible for him though after that happened and he had nightmares because of it. PS I loved his son as Jethro Bodine in The Beverly Hillbillies.
He'd be a top 25 puncher today but I doubt we would ever hear of him. Maybe Christian Hammer level in terms of actual ranking.