I've been flying (and doing well with) an Imperial 5-ship list with Vader (no engine) flying in formation with Howlrunner and three BSPs, and all five ships have Crack Shot. Howlrunner has a Shield Upgrade -- she's about the only ship I'd consider it on, but it's nice to have the extra protection on such an important, fragile ship.
I was thinking, though, that since I already don't have an engine on Vader, maybe I could be a little more aggressive and drop Howl's shield for Homing Missiles and Guidance Chips on Vader. With focus, chips, and ATC, he'd have a 74% chance of 5 hits/crits, plus Crack Shot to help them get through.
Assuming he spends his focus on offense, that would leave him defenseless, though. Maybe not such a bad thing since Howlrunner next to him may still be the more attractive target.
Darth Vader + Homing Missiles + Guidance Chips + Crack Shot + ATC + TIE/x1 (36)
Howlrunner + Crack Shot (19)
Black Squadron Pilot + Crack Shot (15)
Black Squadron Pilot + Crack Shot (15)
Black Squadron Pilot + Crack Shot (15)
Total: 100