What system is hardly irrelevant. It's about enforcing whichever system you set forth. The only difference is that FFA doesn't require enforcing, any and all other system, if there is a system, require some kind of enforcement. This applies to not only NPC but also base and planets.
If a legion can't enforce its own rule, that's their own problem. There is no reason for Dan to make a kiddie glove for them, he can do something better with his time.

First time we boot em and let them back in. so no LMs or bases and such for a week. After that, you're gone for good. there's your enforcement

That's a good way to lose members though. Not all legions can afford to do so.

Also a good way to punish the whole legion at the same time. I know if I were to get kicked from a legion like that, I would find another legion.

Always welcome in our legion You may know a few people...

Yeah, ok. I'll put away my jewel encrusted gold crown in a top 20 to go to a backwater legion I used to abuse when I could still see them... Thanks but I think I'll keep my invulnerability.

Ouch That didn't hurt one bit...

Don't worry Bandit.... You only get a bouquet in top 20, it isn't till top 10 that you get jewel encrusted gold crowns.

D Flag must be wearing a fake :/

Yeah, who'd want one of those crowns, everyone jockeying for it. Our leaders aren't here to tell people what to do, but to support them on the battlefield and in the base...

Sounds like a made for TV movie to me