Final campaign - "Too Bright for Darkness [Campaign 7 - Mission 2]"

By the way, has anyone played through the final campaign as a Knight, focusing on the path of war? I played through it as a Necromancer, and it was manageable because after battles against armies like Ishtvan's, the losses, while unpleasant, are not devastating, like losing 80 ghosts, but they can be re-recruited due to the constant availability of slaves. But what about the Knight? It seems unlikely that resurrection, healing, or restoration will allow you to win without losses, especially since this is a battle where your army is only slightly larger than the enemy's. And I also noticed something strange: diplomacy works for Knights, which was a pleasant surprise when 600 more units joined my 700 archers for 60,000 gold :-). But for the Necromancer, not a single unit joined from the beginning to the final campaign; does that mean diplomacy is completely useless for Necromancers? And can a player or bot see your Ash's Tear on the map? For example, if you collect four Shantiir discs, and it appears right under the bot's nose, will they grab it, or will they not see it?