They're exclusive or associated with that Clan.
Bravo Trinary
Summoner 5/8/5 – Thresher 5/8(10)/5 - Black Python 5/8/5 (CSV)
Nova D 5/8/5 – Great Wyrm 5/8/0 - Huntsman Prime/A/C 5/8/5 (CNC)
Thresher 5/8(10)/5
Champion C 5/8/5
Firefly C 5/8/4
Summoner is an option, but maybe you don't like omnis in your second line. So you take the Thresher. You're not a Steel Viper, you you don't take Black Python. Or you do, all optional.
Let's say you are a Nova Cat, so we have the choice between Nova, Great Wyrm, and Huntsman. We already took an Omni 2 omnis seems like a lot for second line, so Great Wyrm.
The others are all generic enough that they should be fine for any Clan. The Star is Summoner, Great Wyrm, Thresher, Champion, Firefly.
Hope that makes sense.
edit: also, I realize some may not be to that Clan (Mandrill with Smoke Jags), but that Clan either shares some planet with the original Clan, fought just before REVIVAL with them, or I really needed a third for that Clan and it was my best option. It's why I made this post to see how badly it offended others.