I have a 5e D&D campaign right now that is very successful. Right now I have 10 players in two groups, each group playing once a week. However, recently I have had 6 more people who want to make a third group and I'm not sure I have the time myself to run and prep for that many sessions per week. The groups are in the same world, but not running the same plots.
So, it was suggested that I ask some players to become assistant DMs to help with prep and plotting, but I'm not sure what tasks I could realistically delegate, or how many players would be appropriate to have as Assistants.
What can Assistant DMs effectively help with, and how many would be useful for our group size?