Well my main will be my druid as every expansion. Then I will need my herb alt which this time will probably be my shaman, likely resto. Then i was planning on leveling a tank alt, my warr. Not sure what after that as I do have every class but I will wait on how fast the level experience is and how time consuming raiding/m+ will be.
So in short.
Druid - Balance
Shaman - Resto
Warrior - Prot
…?