That's right, the Squadron name would be the first part of the call sign. Maybe it would be more fun to each choose a callsign of our own, like in Top Gun (Maverick, Goose, Ice Man, etc). In that film both pilot and navigator had their own callsign.
I've also been thinking about the roles each craft would play. I think the Y- and B-wing should be wingmen, and they would be our heavy element. The two X-wings would be our strike element and my A-wing would be recon and support.
By the way, if we do decide to come up with our own callsigns, Rayf could be "Jaggalor".