During the mid-to-late 90s (prior to even the Prequels), there was an explosion of Star Wars Expanded Universe novels.

Most of those novels concentrated on Han, Luke, Leia and co.

Most, but not all.

Alongside those, there was also two separate series of books, initially taking Wedge Antilles as a key character, concentrating instead on the fighter pilots of (initially) Rogue Squadron and (later) Wraith Squadron, taking inspiration for the X-Wing and TIE fighter computer games of the time.

And those novels themselves - now considered 'Legends' i.e. no longer canon - could very well have provided inspiration for this, the first of a spin-off trilogy (I think) from a series of graphic novels.

Whereas Rogue and Wraith squadron both had their pilots flying the same type of fighter craft, and both were very cinematic in their presentation, this novel - definitely in the first half (which, I felt, dragged somewhat) - concentrates more on its members psychology, with the so-called Alphabet squadron headed up by an ex-Imperial keen to prove her loyalty to the New Republic. And why is it called Alphabet Squadron? Because the pilots fly a mix of starfighter, from an A-Wing (i.e. that which crashes into the Star Destroyer bridge in Return of the Jedi) to a B Wing (the cross-shaped bomber glimpsed in flight), to an X-Wing (the type Luke Skywalker flies) to a U-Wing (The personnel carrier introduced in Rogue One) to a Y-Wing (the initial bombing run on the Death Star).