Ok at this point in time the only way I can see to make a list with 4 ships and fairly high pilots is to sacrifice and turn one of them into a plain A or Y wing. With this list I would rather have the A as that 4th ships roll will be tilted towards late game closing. Something I think that the dial of the A wing will aid with more so than the Y. So with that in mind here are my thoughts.
Luke R2D2 + Swarm
Blue with FCS
The entire squad will stay together but slitghly spaced to attempt to split fire up. Biggs will take one flank covering the Blue in his protective bubble. The Prototype and Luke will take the opposite side. Luke is more often than not a target no one wants to waste shots on early and if people dedicate fire to take out the prototype then its been a 17 point bullet magnet. Hopefully I get half to shoot biggs and half to pick a different target due to firing arc restrictions.
If all goes well everything is alive past the first two turns. Blue is doing his TL focs business and the 2X's and a are picking other targets. Meanwhile Luke swarms whoever is advantageous and firing order is 8-8-5-2 or 1.
Not sure if it will work as good as it sounds but Im gonna try it soon and will report back.