Discussion about Sylvan (Wood Elves).

So, you're saying that playing defensively against the undead is normal. That's not quite right. What will you do? Wait for the opponent to use Forgetfulness or Blind, or Mind Control, or Berserk, as Major Vortex already explained in the previous post, or hope that archers will be saved by the resistance of unicorns? But regardless of the unicorns' resistance, the undead will weaken your army with darkness while you sit in defense. It's better to attack them first (it would be good to use Haste or Retribution if you have it; then one attack against them can decide the outcome of the battle). If the undead have few troops, then the Elves have better quality and initiative. Besides, if we consider HotA, you can have time to pick up sworn enemies, which is a very good bonus.
If you are going to play defensively against some other race, then Readiness won't hurt, and it is precisely through the "Stalwart Defense" ability that "Readiness" is increased, and Stalwart Defense together with "Readiness" is simply a "bulletproof vest." (This is especially helpful for Treants; they are already very resilient, and with "Stalwart Defense" they become real "terminators").