I am wondering if, with the wording of the Waaaaagh! and Mighty Waaaaagh! abilities, they are only triggered once at the start of the combat phase no matter how many times you use the same command ability on the same model during the hero phase.
"If a Megaboss uses this ability, count up the number of Ironjawz units within 10" of them at the start of the combat phase of the turn, and roll a dice."
So if he uses it, you roll one dice. If he uses it 3 times, you still roll one dice, as there is no counting mechanism installed for adding multiple dice to roll for the same Megaboss (i.e. "roll one dice for every Waaaagh!"). This would imply that using multiple bosses it can be stacked, as each has their own Waaaagh! but it can not be stacked by the same boss multiple times.
I am wondering how to interpret the RaW and even RaI for that matter.....
much confusion,
Mark