For me, there is no difference between a minion and a non-minion.
A kobold skyblade is a kobold who has some special training. He knews a few combat tricks other kobolds don't know. He might have some experience in a few battles in his "backstory" so he's a veteran of battle.
A minion is none of those things. No training, probably not a veteran of battle. But he could still drop his javelin and fight with a short sword. He might still use a dragonscale shield from a fallen companioin. He is no more likely to be wearing rags than his fellow kobolds in the cave, including the skyblades, although he might not have any armor at all.
When a mixed horde of kobolds comes running out of the darkness, or from behind overturned tables and chairs, or whatever (kobolds love their ambushes), it might be hard to immediately spot which are minions.
As for the characters, they've never heard the word minion, except as a term for expendable battlefield forces.
But they are switnging swords and axes, firing bows, and casting deadly spells.
Just like here on earth, where a single sword stroke, arrrow, bullet, etc., could kill you and me, so it is with the weapons and spells the characters employ.
Sometimes they hit a kobold and drop it in a single shot. I certainly don't describe it as "you graze the minion's shin with a skin-deep fleshwound, and then it dies." No, I describe it as a "solid blow tears through the kobold's chest, sundering muscle and bone and organs, and the kobold dies."
Likewise, sometimes they hit a kobold, roll damage, and the kobold shrugs it off and kepps attacking. I don't describe it as "your sword rips open the kobold's belly, spilling intestines and organs out in a bloody mess, and now it looks mad as it prepares to hit you back with its own sword." No, I describe it as "you swing for the kobold, but it leaps back, narrowly avoiding a lethal belly wound, though your sword still slices a shallow wound across the kobold's flesh. Now it looks mad."
Sure, the players have knowledge that lets them sort out which was a minion, and which wasn't - after the fact. And they are usually astute enough to work it out during the fight, and take tactical actions accordingly - this amounts to a real world combatant surveying the battlefield and realizing that some enemies are fairly deadly, and other enemies are weaker, new recruits, less battle-hardened, green, cowardly, etc.
But to the characters, they know they really let one kobold have it, and the other kobold got out of the way in the nick of time.
To the characters, there is no concept of minion. Just some kobolds, or orcs, or goblins, or undead, or enemy soldiers, etc., who they kill in one shot (because they hit the enemy somewhere vital) and some they don't kill in one shot (because they only scratch/bruise/graze the enemy a few times before they get in the killing shot).
That's my take on minions.
And to enforce this play style, I often (not always, not even usually, but sometimes) switch around the descriptions of monsters. Maybe that kobold minion over there is wearing chainmail he looted off a dead halfling, and is flailing about with a battle axe he stole from an orc. Maybe that skyblade ran away from some fight a week ago and lost his swords, so he's fighting with a javelin. And maybe that shaman in the back is just clever enough to carry a shield and javelin into battle to disguise his true nature from the threat, so he can get into position to unleash his devastating magic on some unsuspecting enemy cleric in the back.
Who knows, maybe this is a room with 2 skyblades and 12 minions, but the minions are new skyblade recruits, freshly equipped with the right armor and weapons but no idea how to use them yet - go ahead, players, find the real skyblades in that mess...
All of which keeps the players guessing, sometimes, so that they take every enemy as a real threat - which is how it should be.
