If you are trying to target tourney players an indoor field will not survive, turning dollars on rental and recreational players is the only way to financially make it, plus you will need a facility large enough to accomidate "your goal". If having an area large enough for 3vs3 paintball is your goal... then you need to atleast doubble you goal!
Population is also a large contributing factor, a place such as minneapolis and surrounding suburbs has millions of people, the desolate landscape of North dakota... idk, advertisement and marketing could help pull more players into your buisness, but then you will need that resourse and knowledge of who and how to target. After you get the customer to walk into your doors and want to experiance what it is you have to offer you will need really REALLY good staff to provide them with a positive experiance and come back, and possibly bring back a few more players.
With that being said you will need someone with capitol who is willing to take a BIG risk with their money. Or "find somone that really doesnt care and just wants to provide some awsome recreation and life experiances"