Tactics for playing as the Sylvan faction.

Thank you for the response!

In general, I also came to the conclusion that Leadership is unnecessary for the Elf.
The only exception... it might be worth trying for a level 20 Wingael. Sacrifice Defense or Light for Retribution.
This is, of course, very risky, because if the opponent uses dark magic, without Light, they will control the archers, cast a bunch of nasty mass spells, and this could be fatal. The same applies to Defense. If the first swift attack doesn't destroy half of the enemy's army, then without Defense, the Elves will take a serious beating from some Orc. But still, there is at least such a prospect for using Leadership.

I'll have to try leveling up an Elf in Chaos. Just out of curiosity.

An Elf in Chaos is very effective. But if we're talking about what to sacrifice for Retribution, I would sacrifice not Light, but Defense, because Elves already don't have great Defense, and without magic, it's even worse. My choice is Light, Logistics, Attack, Leadership, and Luck. There are good perks in Leadership. Speed Aura, Forest Leader. And in general, +3 Morale for an Elf-Warrior will be no less effective than for a Knight. So, it's better to sacrifice Defense in favor of Retribution, Morale, and Leadership perks.

Added 5 minutes later

Lion Set is ideal (we'll have two Empathies then).

I don't think there will be two Empathies. That's too much. How do you imagine 2 Empathies? Do you think the hero will move 20% on the scale? I don't think so, in any case, only 10%. So, if there is a Lion Set, then Empathy is not needed; you can choose other skills and perks. And if there is Empathy, it is better to fill the artifact slots with something else, rather than a Lion Set.