Duplicate Actors

I think I might of posted this before but there tends to be errors in the credits when you get actors with common names. For instance, for the movie PCU (1994) both Gary Cooper (who died in 1961) and Thomas Mitchell (who died in 1962) are credited on Listal as being in this movie. I've seen other actors with common names (and other deceased ones) being credited for movies they weren't in. I guess there needs to be a system set up something like IMDb's where they use roman numerals to differentiate between the actors.