I used to manage two teams when I first started playing this game,I really enjoyed playing on both the id's initially but later on I gradually lost interest since it was quite hectic to manage both the id's simultaneously and now I just play on one id while the other is there just for sending gifts..
I used to play different formations on both the id's earlier but later switched to similar formations...
If you have time in your hand and patience to manage both of your team's equally then go ahead...