But surely you can't make another film and call it Rocky, Terminator, First Blood, etc etc
You can make a film and call it Button Man because, despite your use of '
another film and call it Rocky, Terminator' etc, there is no other pre-existing film called Button Man.
As already said, 'button man' is a gangster slang term that's been out there for decades (It's used in dialogue in Godfather Part 2, in 1974. Should Francis Coppola and Mario Puzo sue John Wagner for using it?)
You can't copyright slang expressions, commonly used phrases etc.
If someone did a movie called Button Man using the premise of the Wagner & Ranson comic series, then that would be a different matter.