This video is a tutorial on how to manage guard spawners with a device. It calculates an approximate strength
(threat level) for each team based upon number of players, then spawns guards to make the teams slightly more even. In my map, I use it to provide some basic defense for capture points.
https://dev.epicgames.com/community/learning/tutorials/pvn1/fortnite-spawner-devices-and-basic-testing