Without buying units

[fable]

Having finished the game on impossible with warrior and paladin, I thought I'd try something new to make it challenging with mage. The idea is that I won't buy any units. I wonder if anyone else tried that.
I'll miss Sleem, because I can't buy the snakes for him. I'll miss dryads as well. I hope playing mage is really that much easier than the other 2 to compensate. I think if I find some green dragon eggs I'll be fine.
I'm up to level 10 with full stack of vampires, ancient vampires, griffons, and sea dogs, thanks to sacrifice. Sadly, the first time I couldn't find sacrifice anywhere, not even in Demonis, so I had to restart, even though I had canoneers joining me. This time it was miners only. At the beginning I also restarted a lot of times until I found some ancient vampires in the cementery. There are about 10 sarcophagus and each has a slim chance to have them.
I also found a neat trick to get through the turtle boss easily, by chain casting mana spring and last hero on a sprite, which stood front of it. In theory a simple sprite could take out the turtle in 5000 turns