They are both billionaires that have a playboy persona yes, but personality wise they aren’t remotely the same. Even Christian Bale’s Bruce’s and RDJ’s Tony Stark. Tony Stark is more sarcastic and cracks jokes more often. Bruce is more stoic but filled with rage. Also Bruce is a much darker character in comparison to Tony. They definitely have their similarities. Marvel used a lot of DC character stereotypes when making their superheroes, but I see Batman and Iron Man’s personalities as opposite