Tactics for Dungeon.

I played it. Your point is valid; I meant that they would be targeted immediately and all at once. The snake is defeated with one hit, and only the wyvern remains...

You forgot about the guaranteed possibility of creating wyvern monarchs, and when there are 50+ of them defending against a dozen native level 6 units, and maybe 20-30 simple wyverns from the hives, with skillful play, it can be a game-changer... It's not necessary to fly in and hang around, wait, and attack from a wait position; I assume you know how to do that since you said "I played it"?