What happens if I take 4 Shuttles with upgrades (no cannons)?

I clearly beat two Falcons and most lists with two Firesprays as core. How do I do against 4 rebels, tie swarm and 3 firespray?

Should have a solid shot against most lists. I think the biggest issue will be 4x RGP lists and the like, and possibly Phantoms. Making one shuttle a Doom shuttle and the others with Engine Upgrades ought to help there, however.

I have no experience against Phantom. It seems like they might be able to get a lot of unanswered flank shots.

I think I am OK with 4 X-wing Rookie. I am more worried about e.g. XXBB.

The Lambda Omicron is approximately equal to X-Wing Rookie (3 red - 1 green = 2 dice vs 10 hp; 3 red - 2 green = 1 dice vs 5 HP) assuming that you are both in arc (which I know is an issue with the shuttle's dial) and have an action (again, an issue if stressed). However I'm pretty sure most X-wing players won't know how to fight against 4 shuttles and I have the option of engine upgrade, targeting computer fire control system (going to stressed a lot) or antipursuit laser in the blocking shuttles.

The problem I have with XXBB is that I think B-Wing is > basic Shuttle. If I upgrade shuttles heavily, I can't get 4 or I have to take un-upgraded ones, which will suck.

Four cows with anti pursuit

And tactician or fire control system for flavor.

It is 40 damage they have to dish out and you can turtle them so in short it's brilliant.

I am not sure what benefit Tactician would give?

Fire Control System is there to provide free target locks and make up for actions lost to the Shuttle's maneuver dial.