If it's organized well enough you can have a club with a large number of people, it just has to start small and gradually grow. The club I'm a part of now has around 60 members and we have a really great system in place, granted we run dogs so general firearms is primarily hunting together. If you're looking to manage the wildlife, smaller numbers does make it easier but it isn't impossible with a bigger group. The more people you have, the more access you have to labor and capital, so you'll have to decide what the equilibrium is for what you want. Mojotex made a lot of great points, I would just add that if you are going to add other people into the equation you need to have a system to hold everyone accountable for their portion of the burden. If you get the right people involved, I see this being very rewarding.