I've come up with actual names for the variants and here's my opinion on your ideas for the individual variants:
Compact drones: I'll be sure to add a heavy-duty offroad truck-style light bar to their chest plates in addition to painting them a bright neon color, but wouldn't a huge Undeserving Circle emblem achieve the same effect as a target instead?
Soldier drones: Sure.
Melee drones: I'll make their eyes a sharp, angular sunglasses shape unless you were thinking of a different style of sunglasses. I was already going to make them vaguely act like overly self-confident pushovers that would totally say something stupid because they think it's cool, so great minds think alike.
Charger drones: It won't be on the height chart, but I'll do it for individual Chargers if I remember to.
Flier drones: I was already going to at least have them dismembered, but now I've realized that I should have them dismembered at the waist, with the torso spiraling out of control into the air. I was also thinking of a death I've nicknamed "engine failure" because they shoot up into the air damaged, only to suddenly lose thrust and slowly flip over and flop into the ground, upon which they explode. They'll also definitely get caught on things while trying to escape and get slung into a wall while flying at 150-200 MPH.
Wrecker drones: Mmm… I dunno man… I was gonna make them tall, bulky and fanatically swinging a flail around constantly. I'm not getting this one too much, it's just not clicking with me…
As for voices I imagined them all having British accents and the usual deepening and distortion associated with big mean robots for obvious reasons, but:
Compact drones have a harmless, "cute-and-cuddly"-sounding voice that would be more appropriate for a character from a children's show than a cheap, compact instrument of war. I was also considering making "Oh no…" a bit of a catchphrase for them.
Soldier drones sound average, aside from having the slightly deepened and distorted robot voice.
Melee drones sound like a generic, young shonen anime protag (but with a British accent) and frequently spout terrible one-liners mixed with the usual stereotypical karate sounds ("Ha!" "Hya!" "Hoo!" "Hrrraaagh!!!" "Take this!")
Charger drones shout everything and if it wasn't for the Digital Millenium Copyright Act, they'd probably scream "WAAAAAAAAAGGGHHHH!!!!!" on more than a few occasions.
Flier drones have a confident, unduly upbeat tone to their voice similar to the Melee drones, but in a more grounded and less delusional manner than the Melee drones' voices. Think more of the young, optimistic main protag of a mainstream live-action TV show.
Wrecker drones, I wasn't think of them talking much, considering that I was going to limit all drones to only spouting one or two generic non-plot-relevant lines and the usual grunts and groans of pain at most, but I imagine the Wrecker drones would have deeper than normal voices and say little more than grunts and groans of pain when hit.
Brawler drones (The TOG IIs) would largely be the same as the Wrecker drones, but even deeper and with the occasional "Nooooooooooo…" upon death.
@Quiet_boi
Mini Uzis, got it.
How do you feel about other guns, namely double-barreled (perhaps even quadruple-barreled) shotguns, break-open 40mm grenade launchers, service rifles and carbines?