I'm collecting three with the main hero, one with the weakling. No meat at all. Just XP and gold.
Twin GO - nagas and gr. minotaurs. I pass through the nagas on 124 still without oil, and still can't level up Earth magic enough. I sit in a dungeon right behind the GO, hoping I might catch something in the center. And...
And I find myself trapped between gr. minotaurs on the way home and arch devils on the path to the center. And still no oil.
I break through, sacrificing half my army against the devils, and on 126 I sit in the central town (to replenish mana from zero, finally with oil), picking up a pack of efreeti from a box along the way. Where Crag Hack with roughly three times the army overwhelms me.
And if I had saved one day of tempo somewhere, I'd have had a chance. There was a Tome of Air Magic nearby, and at home on 131 there was already a pack of black dragons.
I made a mistake in the report - the game ended on 126.