oh yar, deathclaws CAN climb ladders after you.

Begin the Quincy town hall mission. Place one squad member on the town hall roof near the siren to act as a spotter. This allows you to see patrolling beastmen.

Use the fence opposite the front door to stealthily approach a ladder. Climb the ladder without being detected.

Equip an AK-47 and use Rage with high stealth (85%) to eliminate the roof guards. A full burst at close range from behind will kill them in one shot without raising an alarm.

With the roof patrol cleared, bring the rest of your party onto the roof.

Send one squad member inside the town hall's second floor and have them descend to the first. When a beastman spots them, retreat up the stairs, lure the enemy, and kill them on the second floor.

Stealthily move the group to the first floor and eliminate the remaining beastman. This will leave only the Deathclaw.

The Deathclaw does not sound an alarm, allowing you to focus on fighting it.

After defeating the commander, retrieve his key and open the door to free the mayor. Collect the key on the ground and ammo from the shelf.

Go to the balcony, climb the ladder, and disable the global siren. To confirm it's disabled, toggle your minimap to the text box and 'use' the siren control box. You will receive an experience bonus if successful. Note that individual buildings may still have their own sirens.

Head west and south towards the long building with roof access stairs. Eliminate the sentry patrolling the south end of the tracks.

Prepare an ambush for the Deathclaw emerging from the building's porch area. If detected, switch to automatic weapons. Consider setting a dynamite trap and luring the Deathclaw over it, with shotgun and magnum users ready to finish it off. Deathclaws have around 200 HP, hit hard, and move fast.

Finish off the remaining two sentries to the northwest and proceed to ghoul town.

Locate the ghouls in a building to the west. Talk to Elliot once in a secure position. Beast lords, dogs, and several Deathclaws will assault from the northwest.

Use the northwest wall for cover and the fence gap as a bottleneck for concentrated fire (shotguns, grenades, automatic weapons) against the charging enemies, especially the Deathclaws.