The Dwarf’s siege attack completely counters the Elves’. After that, they rely on your strong front lines, and they don’t deal much damage. In the next turn, you use runes that heal your front-line units by 40% (I don’t remember the exact amount), and then, under the runes, you destroy everything. If he risks sending in dragons, even if they attack twice, they will still get a guaranteed one-shot from your dragons under the runes. And if you also have a set that gives two mass buffs to defense and evasion, then even the archers won’t do anything.