Actions

Multiattack The guardsman can attack twice with its longsword or halberd.
Longsword Melee weapon attack: +6 to hit, reach 5 ft., one target. Hit: 1d8+3 slashing damage.
Longsword (pommel strike) (1/short rest) Melee weapon attack: +6 to hit, reach 5 ft., one target. Hit: 1d4+3 bludgeoning damage and target has to succeed a WIS SAVE (DC 14) or cannot take Reactions and loses its DEX bonus to AC for 2 turns (Dazed) unless Helped.
Halberd Melee weapon attack: +6 to hit, reach 10 ft., one target. Hit: 1d10+3 slashing damage.
Heavy Crossbow Ranged weapon attack: +6 to hit, range 100/400 ft., one target. Hit: 1d10+3 piercing damage.
Heavy Crossbow (braced) (1/short rest) Spend 20 ft. of movement and roll dmg twice and take highest result.

Bonus Actions

Whistle As a Bonus Action, the guard can call for nearby reinforcements who will arrive in 2 turns.
Second wind As a Bonus Action, the guard can heal hitpoints once per Short Rest.