Bit vague where Arthur is...? In a car in the car park I'm assuming...there's no ground LOS to the handler and the beasts as they exited from behind their van (which is facing your way), they are approx. 40-50m from the breech, that's at least long range for a shotgun!
Barghests got 4 hits and 5 hits (not bad on 10D!), -2Agi and Rea for Isaint unless you are going to burn more precious edge? We'll see how the rest fare
Unless Isaint moves he doesn't have an armoured target to see yet (a few sprawled gangers), unless you go back to the breech? Happy for you to 'hold' action and save that roll...
New round, we'll count this as round 1 after RP time

Foes on foot are loosely going on initiative 25, vehicles are around 30
Smoke is beginning to clear, Robyn can 'see' they are also using active ultrasound
Have fun at your festival!
While you are all at it you can resist the next nasty coming your way (Adamu is right, they seem to be after you!) from the two inside the building firing through the breech (assuming they aren't dead before ini 25 anyway...)
Arthur and the Morgan are parked at the edge of our safehouse (on the google maps map it would be parked between the red car and the bus on the parking lot.
Also since you described the Barghest's appearance I assumed they were visible from the parking lot. According to the measurement tool in google maps it's exactly 25 meters to VAN 2 from that parking space, so -1 for distance and they have probably cover - but Arthur also has an enhanced sensor array with all the usual jazz - including thermo vision and vision enhancement.
If you say he can't see them from there, I'd like to change Arthur's action to set the car in motion until he has a firing solution (So one control vehicle action before he starts shooting)
Isaint was the last to leave the building - having helped up Al and given him a push, so I imagine he's still at the edge of the mana static zone and with sight into the building. And yes, he was shooting at one of our pursuers.
I spent a second point of edge to negate the second paralyzing howling:
Edge Reroll:
9d6t5 3 [9d6t5=2, 2, 3, 1, 3, 5, 1, 5, 6]
Total 6, so no problem there.
Sonic rifles next: Isaint will go full defense for those:
Defense (Full Defense):
24d6t5 8[24d6t5=6, 4, 2, 4, 3, 4, 5, 3, 1, 4, 6, 4, 6, 6, 3, 3, 6, 4, 5, 5, 1, 1, 3, 2]
Defense (Full Defense) 2:
23d6t5 6[23d6t5=1, 1, 2, 1, 2, 6, 6, 1, 3, 4, 1, 1, 4, 5, 5, 6, 2, 1, 5, 1, 1, 2, 4]
I can't be sure, but I think I evaded them. Just in Case here the Willpower Soak:
Soak:
5d6t5 3 [5d6t5=6, 6, 4, 2, 5]