I have great respect (and great reader’s appreciation) of late Tom Clancy.
He is (sorry, was) professional.
Before writing the next thriller book of Jack Ryan series,
he was getting embedded himself in the study
of a particular kind of military people and equipment,
was writing quite meaningful non-fiction book about the subject
in collaboration with a (usually military) co-author.
Only after that he was writing the next thriller.
Not a Tom Wolfe kind of writer, and not William Faulkner kind,
but good one on his own merits.
“except for pop fiction of the Tom Clancy variety”
That’s one hell of a big exception. There are many writers, including no small number of veterans, making a good living from just such pop fiction. Some of them are even promoted by various radio and TV talk show hosts.