I'm assuming the cartels are not playable?
If so, you can probably be pretty free with who they like and dislike. I try to keep them at the same allied percentage as the empires (since that is a number that applies to all race slots). So, if I have 4-race empire teams, I would give each cartel 3 allies. I tend to use 1000 for enemy and 0 for friendly to avoid the gray area interpretations the serverkit sometimes spits out. I do the same for the monsters and non-cartel Orions. Just don't make any non-empire slot friendly to an empire, and you shouldn't get bad ally matching.
If you want the Reclamation or Tech Wars tension settings (essentially the same, except Mirak and ISC switched sides), let me know.