I made my way to him with 50 Archangels (Fafner and others), and even then it wasn't easy. How did you manage to take out those Fairies on the way to Rylund with that meat-shield army!? In theory, all that meat should have been wiped out in the very first turn from attacks by Fairies with stacks of 80.
The battle is not difficult, see screenshots. You need to take Crystal Dragons (a dozen would come in handy here, but 8 are enough). The screenshots also show Mages for cost reduction and Genies (since there's simply nowhere else to unload them). Round 1 — Anti-Magic, obviously, then we move to the center to be able to break out of the encirclement. Round 2 — cast Armageddon with the Blade (minus 6 Faerie Dragons per stack), move to a corner so that at most two (rather than three) units can hit us. Rounds 3 and 4: Armageddon and defense. Rounds 5 and 6 — blind the neighbors (we have 1 Dragon left, can't withstand any more hits). Then we wait about 35 turns and blind ALL the Fairies one by one, so that our Anti-Magic wears off while they are asleep. While they all sleep, we recover, buff ourselves (Shield, Stone Skin, Bless) + ANTI-MAGIC AGAIN, apply a debuff — Curse, and start blasting with Armageddon again. Blind the last Fairy, resurrect everyone. Victory.
I took them on with Girld, 50 Archangels + 536 unupgraded Elves + 3 Pegasi (upgrading would lose tempo). I wiped out all the shooters, finished off the remnants with archery, and used up almost all my mana.
Well, your mistake here is that Kir didn't come to the sand respawn and upgrade the Elves to Grand Elves in the fort. Of course, the striking power of Grand Elves against the Cows increases significantly. I managed to defeat the Cows with only the loss of a few Flies.
Regarding Crag, I just loaded a save specifically — there's no Bow.
What am I doing wrong?
I started the map from scratch — and there was no Bow either. I've been playing for years, and I've never heard of the bug where the Bow appears in the backpack. I'm not to blame here! We'll still get the Golden Bow early on (a substitute of sorts), and the Bow of the Sharpshooter will eventually drop from someone. In short, the bug helped, but it didn't critically carry the match. The main artifact on the map is Armageddon's Blade.
The map might be fine-tuned for the perfect walkthrough (the author knows best), and we might see it somewhere on a Chinese forum :) I made the review not to show how cool someone completed this map, but as a way to popularize the heroes, if you will. The map deserves attention.