Discussion about Sylvan (Wood Elves).

I'm playing as Dirael on the "Disputed Island" map (medium size) at the hero level. There, phoenixes guard a narrow passage to the center of the map – you need to break through it in any case, and the sooner, the better. At the "hero" level, there are few resources, and there are few on the map itself.
Question: how, playing as Dirael, is it best to destroy the phoenixes at the beginning of the 3rd week, or at least the 4th?

I completely agree with Soljie, but in addition to what he said, I would add either using speed boost on the archers or slow down on the phoenixes (if such spells are available).
And in general, it is best to develop like this:
1) First, upgrade the Avenger (trained, skilled): volley, enchanted arrow, and deadly shot.
2) Be sure to upgrade logistics, luck, and magic of light. (can be in any order)
3) Logistics: Silent Pursuit, Find Path -> Native Lands
Luck: Soldier's Luck, Luck of the Road -> Elven Luck
Light: Righteous Fury -> Storm Wind -> Secrets of Light
4) After upgrading "Native Lands", "Elven Luck", and "Secrets of Light", be sure to upgrade "True Luck" (all troops will attack with luck in any case, even if you have -10).
If you only upgrade these abilities, everything will be ready by level 25, but believe me, it's worth it.
P.S. Ossir and Ilfina cannot use this guide.

Guys, help me, I can't upgrade the last stage of the Avenger, "Ruthless Avenger". Tell me what I need to do, maybe kill someone or something else.