On the contrary, I can totally believe it. Historically officers have come from nobility and if you watch something like Sharpe or Legend of Galactic Heroes, you’ll find them fall into one of two categories; either the combat pragmatist who actually concern themselves with tactics and strategy that not only bring them victory but do so at minimal loss of life, and are thus indifferent as to whether a fellow officer came from nobility or rank, and thus come across as far more sympathetic not only to the troops under their command but also the audiences - and the stuffy nepotist blue blooded brats who feel entitled to their rank solely because of their lineage and absolutely despite the plebeians regardless of what their current rank might be. The former usually become allies to the protagonist of the story (who most likely came from the ranks) while the latter loathe their guts and either die or become broken and humbled, or in rare cases, actually become better people.

Fancy Pants definitely feels like the former type.

I’ve actually been thinking about having something like this in my fanfic for a while, saying he was a Retired Guard, and Currently The Mayor of Canterlot.

@Kamazeustra  
He surely has the aura of a war veteran enjoying his civilian life.

@Evowizard25  
Haven’t seen any real evidence of that.
 
@Kamazeustra  
Who’s to say there’s a draft at all?  
He has the bearing of an Officer and a Gentlecolt.

Look more likely that the armor is rbbing him the wrong way.

@Kamazeustra  
Equestria has a sort of feudal system, so it’s not a stretch to say that nobles would participate in warfare.

Equestria must be in dire straits if the rich aren’t able to buy their way out of the draft anymore.