Well, I try not to have special cases like this in my code, unless it's a common enough case that warrants the technical debt.
It's generally not an issue for popular movies, because FileBot knows all popular movies, so it doesn't matter if there's junk before or after the movie name, kinda like a human would immediately identify files, not with patterns, but with knowledge. However, FileBot has limited knowledge about 1920ies movies, so in this case it doesn't work, even though it would work for 12.Avatar.2009
Though, looking at it the other way around, I might consider ignoring leading numbers, and then rely on knowledge to identify 12.Monkeys
and friends, as there is a naturally limited number of movies that start with numbers.