Balance in Heroes 5.

Damn, I'm not talking about defensive towers and walls, but about the tower that gives you half of your army as level 1 dwarves. And they are, practically, the most durable and armor-piercing level 1 units.

Let me explain for those who don't get it.
You summon a phoenix, place it near the Castle gates, and not a single dwarf will pass through!!! Meanwhile, you shoot down the main army, since you have 3 stacks of shooters. Or do you think that 2000 dwarves will take out a phoenix in one hit? Even five might not be enough! The dwarves, of course, can hope for Armageddon or a lucky Magic Oversight rune. But mages also have creatures immune to magic, the Magic Mirror, and you can set up same-magic protection in the mini-artifacts… So… where is the obvious advantage here?