Firstly not sure if a 5 ship squad counts as a swarm but in reply to this..
I run a 6 ship list with Howl, Mauler and BSPs:
Howlrunner + ARush +Stealth
Mauler Mithel +ARush
2x BSP + Arush
2x BSP + DTF
I will advocate AR on BSP at every turn, and have found BSP+AR superior to Night Beast.
This Saturday I came third in a tournament of 18 players with this list
Howlrunner + SqL
Black + DTF
Scimitar + APT
Scimitar + Assault
Gamma + Concussion
I had only flown this list once before the day and that was with 3 scimitars one with a seismic otherwise the same.
with more practice I think I could have done better and the last minute change to a Gamma screwed me over a little in one game but otherwise was redundant so shouldn't have made the change.
I do think this could be bettered and have been trying to tweek it since but have no clear answer yet.
The problem I encountered was in manuevering the mix of PS 2 and 4 in the bombers so am thinking of dropping one bomber and taking two Gamma or going back to all scimitars but will post when I find a solution and will also write a battle report over next couple of days.
The one thing I liked about the 3 bombers was the mix of ordnance for all occasions a bit like a Swiss army knife.
I hope this inspires you Liz