Ranger – “Emerald” [5th campaign, 2nd mission]

In the first week, we clear our entire island, except for the passage downwards, WITHOUT any losses.
Then we buy troops (preferably already having ents in the castle).

Are we playing on easy or with cheats?
and giving advice, giving advice...
Neither with subjugation nor with resurrection could I defeat 18 Overlords with 17 elves in the first week.
On the generally accepted maximum difficulty, ents are built with difficulty in the second week (if you build elves).
I started the mission ten times - I can't pass it.