By early, I mean Lewis when he was 21 fights into his career like Joshua. Who would win? Lewis had a better jab and faster hands, but he had a tendency to get a bit wild. You could argue that Joshua has fought better opposition than Lewis had at that point of his career.
I'd say 50/50. Lewis had a better developed skill set, but on the other hand could be timed. Lewis early in his career had a bad habit moving his head too far to the left when avoiding jabs, which Joshua might figure out like McCall did.
