Braddock is just a name change for the original Montgomery character in the original 1896 classic novel. Just try to accept the Braddock character as a slight alteration from Montgomery, the name H.G. Wells originated for basically, in most ways, the same character. No biggie. But even though Val Kilmer's role was in SOME aspects a little closer to the book's, Michael York provided a much better performance as the Montgomery character. And even although storywise the character is in some ways different from the one in H.G, Wells novel, York's performance of the man who turned into an animal, was far more competent and beneficial to the movie's value than was poor Val Kilmer's, since he was subjected to such an absurd co-performance by Marlon Brando, who made it difficult for Kilmer to improve the credibility of the story. Although Kilmer wasn't that credible as Montgomery, anyway. York was far better in the role.
Anyhow, don't blame the movie just because they changed the name Montfomery to Braddock in this, the best version of the story, despite it's variations from the Wells 1896 classic, which by the way, was written almost an entire century (81 years) earlier (1896 and 1977). It's called artistic license (which in this case is acceptable due to the 81 year lapse) when the film version is allowed some polite forgiveness for varying from its original source. In this case his name change was probably altered since the script's changes make it easier to accept variations in (merely) the names of the copied counterparts to the original characters of the book. That way less criticism is warranted for the script's discrepancies, since no xerox copy of the role was intended, proven by their changing the character's name from the one (Montgomery) that H.G. Wells invented in his fertile imagination.
But I love to watch Nick Cravat (M'Ling, Montgomery's bear/human servant who, in this case was given the same name as the original H.G. Wells character from the book) act alongside his old circus partner, Burt Lancaster (they went by the names of Lang & Cravat in their old days in New York City before they left for Hollywood to achieve stardom). They've been in so many enjyable films together and they were the greatest of friends, despite Nick's explosive temper, and Burt's egomaniacal vanity. It was fun once again watching them act together, two of Hollywood's GREAT cinematic stars and also great friends that passed the test of time, both cinematically and longevity-wise (They were born 2 years apart and both died in their 80's in 1994, coincidentally, the same year, although Nick died about 10 or 11 months earlier than Burt, despite outliving Lancaster by 2 years - Nick was 82 and Burt was 80 when they passed).
Montgomery was a different character altogether. The main character was called Edward Prendick in the novel. York played that character, only they changed the name to Andrew Braddock for the 1977 movie.