Gang spar was pretty famous in the older times and a lot of gangs and players had fun participating.
Just by adding rewards it will revive it and give gangs a purpose other than basing. I would also love to see a leader board (1st,2nd,3rd) place somewhere in the building to the top gangs.

If it’s successful I would also like to recommend a secret spar arena for gangs who have won a certain amount of spar wins similar to the reward of a hide out for a basing gang. There is a lot of good secret levels in era that could have an arena and maybe even a gun skin. Of course this would give also keir some extra work haha.