At fights when there ir many stacks of dragons scattered around i used a bit cheat tactic, but from other side absolutely legal (and used it only when there was more than 2 large stacks of dragons).
I putted all my armies except dryads in garrison/reserve.
In 1st turn (because i have points in +init skill from warrior tree) i casted 2 armageddons. Dryads used summon. In second round black dragons went 1st, at dryads turn 1 or 2 armageddons then "wait" (to let them hit my dryads) and then skill "Time back" (3rd of 4th spirit skill). So situation at the end of 2nd turn was: my dryads ar absolutely unharmed and there is minimum 15-20 less dragons in each stack.
