If you don't fight this battle with Kilgor, the enemy will have more speed, and the Alliance of Angels' prayer will activate sooner.
Now I'll illustrate this mechanic more vividly.
By the way, I've been meaning to thank you for the trick of destroying an unnecessary (spent) Archangel clone using the Wall of Fire: I used to do it with the Ring of Cold, but this is more efficient (6 mana instead of 9). It's a shame that the Wall only lasts for 2 rounds. And I didn't come up with the trick with the Ring myself; I read it somewhere before (in Richard Chen's video, he uses the Ring). It's easier during a siege because the used clone is killed in the moat without spending mana on a spell. By the way, the most impressive thing is the small army Chen uses to win this battle, and there's also a strong dependence on random factors (especially: who and how the fabled creatures will attack).
(Василь Симоненко. Люди – прекрасні)