Thanks for the tips Saridu.
I would add a recommendation to try out the Alchemist Dwarf Level 4 units in the Swamps. They are my strongest unit at the moment: I'm Level 7 before going to Freedom Islands on Impossible.
Not a single Inquisitor in sight.
No Resurrection Spell.
No Sacrifice Spell.
Which reminds me, does anyone know of a sure way to get any one of those three?