Increase dues and reduce through attrition.
Having the wrong members is worse than having too many members (within reason), imho.
In our club, we had some members that would scout year round, walk very far though the woods to get to their stands (messing up the woods for everyone else) when there was a much shorter route, and so forth.
When they got out of our club, the overall deer population relaxed somewhat. We could see a noticeable difference even in the first year they were out. They (6 hunters on 3 memberships) would hunt every weekend and always hunt somewhere different each morning and evening. The had a lot of personal stands, so they were always walking in the woods. I understand about hunting hard. I've done my share of packing in climbers miles from where I've parked, climbing up before daylight and climbing down after dark from the same spot, but each trip to an area has an impact on the deer.
We hunt over 4000 acres and now there are about 10 of us, at most, (including kids) that hunt most weekends. We have a total of 13 memberships which represents maybe 20 different people through the year. Most of the time, we can slip in and slip out of our spots. At one time we had over 20 members and many kids that would hunt. Some areas received a tremendous amount of pressure back then.
I think the right people is more important than the number of people. And getting the right people is much easier, the fewer there are.
Good luck in the quest for having a great club. Just remember that enjoyment is the most important aspect. Not everyone is going to kill a monster each year and there are no perfect clubs.