I know there's been some interest in reviving the Squad Dueling League. The rules could be revisited to bring it more in line with what you're describing.
I'd suggest that it be renamed "Team Dueling League" given that we're currently rebuilding the game and not all squads could likely field 5 people regularly. I think teams should be able to put together a list of any 5-8 people who will participate for 3 months of this (maybe 1 event per month) and have it be bassmaster rules - you can use whatever boat you want, but you're stuck with it all season - meaning no one other than those 5-8 can fly for that team during that season. If you can't field 5 for a night, you fight 4 (or whatever) v. 5 (unless the other team is sporting).
You could have each month have a different objective/flavor. Sometimes AvA, maybe sometimes "fantasy" (what if Germany and Japan fought?), sometimes "dealer's choice."
Maybe for objectives you basically make this a monthly bracket style tournament, results TBD that one night - make all squads show up for the same 2 hours, those who aren't fighting can watch in CM eye mode. Like KOTH, you have a monthly event with a Tournament of Champions at the end. Maybe invite the top 20% of teams to that bracket.
As for actual fighting rules - I'm of the opinion that the less rules you have, the more fun it ultimately is, because there's less chance for someone breaking them/skirting them, and you can just worry about fighting. HO, ganging, picking, etc. are all allowed.
Maybe just have a small, confined area (with mountains, like the smaller KOTH map) to keep people close.
Anyway, another event that encourages fighting would be a good thing, IMO.