Hey!
I don't think that there are any common guidelines on that. AFAIK, in other systems (such as Amiga) there were cases of software released both separately and in collections too, but renamers often selected what they though was better. Maybe Crashdisk and Cassiel can give you some suggestions.
Either way, apart from the selected solution, the most important part is to follow it for every set and don't mix things up, so there is a logical organization that users can follow.
Without knowing much about the system: Those games are not compiled, but instead text files with sets of commands (scripts) that are run in a command line or something? How were they released initially? Some first on magazines, others created and sold? All of them can be read and edited (in other words, source available/not compiled and could be typed in?). Are all of them games? The magazines contained only games? Or it was normal software magazine with some type in bonus games?
Your solution could be used but IMHO "Magazines" could be a bit generic and misleading. Just by reading the datfile name and without your explanation I would think they were some kind of electronic magazines / applications.
It also depends on the number of sets in the collection. Which can influence the number of dats. It can go from as low as a simple:
Computer x - Games.dat, to your option or even a lot of dats with:
Computer x - Games - Compilations
Computer x - Games - Type-in (or Magazines)
Computer x - Applications
(or maybe invert it to:
Computer x - Type-in Programs - Games
Computer x - Type-in Programs - Applications
Computer x - Compilations - Games
In huge systems, it also common to have dats for each type of image, for instance:
Computer x - Games - [TAP]
Thus, I don't think we have a fixed rule. If you believe that your solution is the best option go ahead
