Tony was the Producer, I am not sure whether he directed any episodes but you are right, being the main Producer and Chief Writer, he was hugely influential on how the show turned out and without him, well a film could have been very different in tone. However, with the characters as established as they were, there would have been plenty of material for an experienced writer to use and not venture too far off the track. Actors are very good at saying "My character would not do/say this" to any writers who come in new and green, particularly in well established shows so I think a Follyfoot film would probably have tunred out ok either way.