My favourite mode of play in GoT is archer, but only with the halfbow. The longbow takes too long to aim to be enjoyable as a playstyle and its ammo is too low to rely on more thoroughly in big encounters. The act II enemies are perfect for the halfbow in that they are more heavily armoured than the no-armour enemies of act I, some of them having helmets that require more precise aiming for the headshots, but still allow usage of the bow to do proper damage if you're willing to make the effort to make it viable.
In act III nearly no mongol enemy is unmasked, making headshots with the halfbow impossible as far as I can tell (please correct me if I'm wrong) and just killing it as a viable playstyle. It's very upsetting.