We offered our gear (our own compressor, dive bottles and the team to run it for the day)for others teams to use and only some players came down, no actual teams.
At Swarm even with the School Hall we found it was not quite big enough to run games on, more useful for drills and 1on1.
Founds it very useful once you got used to the balls that missed bouncing back off the wall behind you.
You will definitely need more balls, we used to run hopper drills, so if you have only 3000, then to have 10 people with 100 balls in the hopper, they will only get 3 drills before needing to collect, clean(You must clean them between use) and starting again.