A Song of Ice and Fire: Baratheon: Thorn Watch

While a swirling melee is not optimal positioning for any dedicated archery unit, the Thorn Watch crossbowmen wield light arms and armour, and train extensively with longwords, allowing them to withstand direct assaults which would scatter ordinary archers. Adept commanders will avoid such outcomes if possible, but can rest easy knowing that the Thorn Watch will not wither in the face of a surprise attack. Proper positioning allows these troops to blunt even a vanguard's advance, and protect melee troops from archers or even cavalry.