There should be a plugin that let's you have some reserve slots. So if you have 10 slots in your server, 10 regular players could join and the last few that join will have an "Unsafe" spot, and can be kicked if an admin wants to join, so if there are 3 admins, there'd be 3 "Unsafe" slots. The last one player who got an "Unsafe" spot will be kicked if an admin joins. If there's a "Safe" spot free, the first one who get an "Unsafe" spot will receive a safe slot.
