Perry, The matchmaker at Madison Square Garden who saw Joe Louis multiple times said he didn't have good footwork. Here you have a partial observer who made a lot of money on Louis telling the truth.
You need to watch the bouts in which Louis displayed excellent footwork. Watch his bouts with Max Baer, Galento, Carnera. Louis when he had to nimbly sidestepped, countered THEN moved in for the kill. Generally he did not need to fight in this manner but when he did few could do as well. Unlike many fighters Joe could switch up from aggressive boxer puncher to boxer counterpuncher. Not much Louis could not do well and this is one reason he is rated as either the best or second best hwt ever to live.