Every other Star Wars comic of the early nineties is about the Force. X-Wing Rogue Squadron is about the roster. It opens a few weeks after Endor with a squadron that has lost people, is short of airframes, and has been handed a mission nobody senior wants to explain, and it keeps that register for three years.
Stackpole's long game
Michael A. Stackpole plotted the run while writing the X-Wing novels, and the two projects feed each other without either becoming a footnote to the other. The comics take the period the novels skip; the novels take characters the comics establish. Baron Soontir Fel — Imperial ace, defector, brother-in-law to Wedge Antilles — is invented in In the Empire's Service and is still being written about twenty-five years later, which is a decent test of whether an original character earned his place.
The writing partners matter too. Darko Macan on The Phantom Affair and Jan Strnad on Battleground: Tatooine both pull the book toward moral awkwardness — occupations that do not end cleanly, allies who are not likeable, a New Republic that has to govern the places it liberated.
Edvin Biuković
The art is uneven across thirty-five issues, and then there is Biuković. His four issues on The Phantom Affair are the best-drawn Star Wars comics of the decade: loose, confident, genuinely funny in the faces, and completely uninterested in tracing photographs. He drew The Last Command for Dark Horse afterwards and died in 1999, aged thirty. John Nadeau, who carries the largest share of the run, is the book's steady hand and draws the best starfighters anybody put on the licence.
Why it ended
Not for lack of quality. The last issue shipped in the autumn of 1998; Dark Horse launched its new monthly Star Wars in December, six weeks later and five months before The Phantom Menace opened. Whether one decision caused the other is not something the record settles.
Where to start
Issue #1 works, but if you want the argument in four issues, read The Phantom Affair. If you want the argument in one, read #25.