But you can place Players in existing Planes. And block planes players should not use. Normaly i use two "methods". First i use a spawnplace players can create their planes, after that the Mission-Host can select/start the mission. Friendly KI is supporting the Players if nessesary (depens on the player numbers)
Second i place the Players in existing Airgroups (the player can change the plane if he like via Mission menu).