To add artists to a title, just highlight the title in the browse, and click on Artists. You can then add as many artists as you would like to this title. Because it is related to the title of the movie, you only need to add it to one of the movies and it is automatically added to all of the movies that are spelled exactly the same. (One more reason not to make the title different just because it is a VHS or DVD format!)
This will allow you to do a search from the POS Screen 1 by title and artist, and use the cross reference to find who is playing in what.