The previous movies kept Abe Sapien’s basic background intact, and he was an incredibly polite, well-spoken scholarly individual. So to go from that to a ‘very thug’-like personality is a big departure, though it certainly would have have made him stand out more. Given that this Abe Sapien had also been contained for a long time, we can assume he also hailed from the Victorian era, but perhaps instead of being a scientist, he was a blue-collar worker, hence why he’s rougher around the edges.
Article source: https://www.cinemablend.com/news/2478179/david-harbours-hellboy-sequel-would-have-introduced-a-vastly-different-abe-sapien