“No Attack” stance does not cancel a previously assigned attack order. In other words, “No Attack” stance doesn’t deny previously assigned (and ongoing) attacks, unlike Age of Empires II: Definitive Edition.
Does the unit stop attacking new targets after their current target is invalid(dead or out of range)?
Does it attack new targets afterwards if you give it new attack orders?
Personally I prefer having no attack stance only stop units from auto-attacking. I can put my siege to hold fire and manually target enemies I want to attack. Less flattening my own units.
This is why No Attack Stance should stop units currently attacking. Players BARELY have control over units. Besides, it should be consistent with AoE2:DE, since they’re in the same franchise.