The focus was on doing a quick battle. I only tested it. Since I want to dig every battle in my games, I agree that it needs to be slowed down so that to does not end too quickly - but that is easy with archdemons since they are the quickest unit in the game. In terms of the quickest possible battle (not including bosses) I cannot think of a quicker strategy. Armageddon + Time Back is very efficient.
I do not think it will work with a single red dragon. The reason is that a mage with a high int does too much damage even with Armageddon 1 (they have no resistance against astral damage). The dragon will die and the battle is over. But using a single red dragon and casting spells like Death Star and Geyser might work. The reason I bring a full stack of archdemons when using the Armageddon strategy is that almost half of the stack dies from friendly fire
In theory any stack will do as long as it survives the armageddon and the enemy attacks. It might even be doable using peasants!