Denjiro being strong enemy samurai would be so good tbh.
It's like how Hyogoro was a weakling in Udon as random fodder were stomping him and then he Luffy came around and suddenly the man is pulling out advanced armament and stomping headliners. People who are forced into submission can't be strong since that goes against the rules of the story
Unless Denjiro is like fully a stooge of Kaido and Fodderochi for some reason, him half heartedly fighting for them due to having been forced to fight for them automatically makes him weak