For some reason, only Alan Marlow is credited under his real name in the movie (although his name is spelled differently). Everyone else except for Jean Dalton are credited only under the names of their characters in the movie, not their real or stage names. Only Jean is credited under a stage name.
The title is possibly a reference to the Three (or Four) Musketeers and their famous line One for All and All for One as the final scene is the movie could be seen as a hardcore riff on that motto.