do casualties in the training missions count as real casualties in the final record?

[Vulture]

I've always wondered how a 0 casualties works if you count the training chamber ? I mean, how do you get no losses at the Necromancer mission ? He always casts the big old Axe on a unit which deals 150+ damage and you have no spells yet ---> impossible. I've tried it a million ways and he ALWAYS axes units with less than 150 hp aka kills at least one creature. Since you have no spells and no spirits there's no way to bring back the lost ones.
Plus he doesn't cast Axe only once but every 4 rounds or so.

When I played for no losses I didn't count the training chamber for I dare say that it's impossible to not lose any troops in the Necromancer battle

Correct me if I'm wrong :>