You can do that by default, but the dilemma is that using the default system, the player also has the option to not join a minigame, which we do not want.
Basically youre looking for a multi-default minigame, correct?
what if you have 3 of minigame TDM, rpg city, challege. I join your server, when I am going spawn, pop up gui say:
You would like join minigame select belowHalo TDM
RPG City
Challege
I would choice Halo TDM, I click select it. Then spawn as my red team and other player join blue team. About 15 minutes later, I want switch to challege. I click glow brick bring swtich gui, I click select Challege, then spawn. When you are host in your server. You enable /defaultminigame (force player join minigame) all player are force in minigame. If you has 70 or 80 player, they can swtich of your 3 minigame in your one server. Aslo I did tested make minigame max limited 10. I not want type /leaveminigame.. everytime open my minigame has list, click it and join other minigame, 5 minigame was end. Player can leave server, unable swtich minigame. I hope you understand this. If not, I have make gui and post it here, show you will see it. If you have 70-80 player at your server and how you going make 3 or 5 diffrent minigame. How they can swtich other minigame without ur leave minigame with /defaultminigame.