Flashman did listen to Sergeant Hudson. For the rest - his first servant Bassett seems to.have disappeared believed killed in Afghanistan. Only other dealings with other ranks I can remember with PoWs in Charge and would-be blackmailer Nolan in Dragon - don't remember March very well.
Hudson is, I grant, an exception.
Bassett is a classic example of what I'm talking about. Flashman pays no attention to Bassett save to have him flogged from time to time. And yet, when Flashman goes to Afghanistan, for no apparent reason, Bassett "blubs" until Flashman takes him along. On arrival in Afghanistan, Bassett drops entirely from the radar, and we have no idea what happened to him, and Flashman never mentions him.
It's a crap depiction of an orderly to a junior officer, and Bassett has no personality save that of seemingly worshipping Flashy despite Flashman behaving in a manner that any orderly would take exception to.
The PoWs in Crimea during Flashman at the Charge are an even worse parody of NCOs and Other Ranks.
Without checking, I'm unsure of the status of Nolan in Dragon. By this point in the series, GMF was going through the motions and the books are getting steadily worse.
Aside from Sgt Hudson, I think it is close to say that every single NCO or Ranker portrayed is a pathetic caricature with no more personality or interest than a cardboard cut-out. Which is exactly what they are.
Compare with how Kipling portrayed NCOs and Rankers; strengths and flaws, varied and with a clear voice that still rings true nearly a century and a half later. It can be done. Learoyd, Mulvaney, and Ortheris prove that. But then Kipling had a respect and a clear-sight of the "uneducated classes", and GMF - to judge by Flashman alone - didn't.
God knows, Kipling can be problematic with regard to Racism, Classism, and Sexism. But these problems are dwarfed by those displayed by GMF who is far worse than Kipling in each regard.
I've a good idea what Kipling would have made of me (mixed-race gutter-scum who worked up through the ranks), and it would have been an accurate skewering of me; strengths and flaws and traits and warts and all. I've also a good idea what GMF would have made of me, and I don't think it would be close to the mark.