That’s really not crazy at all. Airsoft scene is pretty vast and large now as a hobby. Here we often have weekly games that hold more than 50 people. There’s the yearly 3 day huge game that’s inspired by S.T.A.L.K.E.R. (I guess, because I never played the games) and holds probably more than 300 - 500 people from all over the Balkans and even central EU. It has NPCs… monsters…zombies… trading… quests and whatever you can think about. You sleep in tents in the bases safe zones and it’s 24/7 action.
Finding suitable island for such thing can be the most crazy and problematic thing in the whole deal, but it’s a billionaire who will get his money back if there are enough people willing to pay huge entry fee to go there and participate if there’s an actual incentive.
I’m pretty sure in almost every country you can organize something like that for really cheap if there are strict rules and you don’t get your guns/gear stolen by idiots ;]
P.S. Local Airsoft fanatics are the crazy people in every country… I’ve seen them carry all kinds of crazy shit and military cannons … geeps… even tanks.