Pretty simple really. Garven and Dutch are there to pass focus and TL to who needs them. r5-p9 is another way for Garven to pass a focus off to Corran for him to use on his second attack if needed.
Putting the R7 on Corran is another way for him to survive, the FCS will give him a TL for defense if his initial target comes after him, if not Dutch can pass him a TL to use on the most likely subject.
I have yet to play test this but I wanted some initial feedback from the experts.
Garven Dreis — X-Wing 26
R5-P9 3
"Dutch" Vander — Y-Wing 23
Ion Cannon Turret 5
R2 Astromech 1
Corran Horn — E-Wing 35
Predator 3
Fire-Control System 2
R7 Astromech 2