Guerilla doctrine is a must IMO. They don't fight "conventional wars", it seems - they pick a glorious target to hunt, the harder the better, and then use misdirection, stealth and psyops (where applicable, not much you can do to psyop an Alien...) as well as terrain use and shaping the battlefield to bring them down. No defending fixed points, supply lines, transporting colonists etc etc.
High Tech for sure, unless your universe has something really hyper advanced.
Mostly infantry, with their weapons being short ranged but punchy and capable versus armour - those shoulder cannons are seemingly pretty damn lethal. Really good close assault values, too.
Stealth AND adaptive camo sounds good. They should rightly be expensive, but very hard to pin down or hit. Combined with Guerilla Doctrine they should be a total nightmare to bring to battle, hitting and fading at will until you can force them to deploy for long enough to plaster them.
Vehicles... I'd look at some good air support - stealth/cloaked space ships, probably single man or small crew types, proper aerojock/fighter pilot "duel in the sky" types would suite their ethos. Ground attack would be secondary but hunting a mega-tank or a Titan in your fighter sounds like a very worthy hunt.
"Ground vehicles" probably skimmers with a lot of punch but no great defences save stealth. Mighty hunter in Land Rover sort of thing, but instead of an Elephant Gun a mahoosive plasma cannon for tank popping.
I reckon you could make a case for auto-linked as they do hunt in packs when they need/want to. A group would split up, harry, confuse and then one worthy warrior would paint the target and the hidden spaceship then disintegrate it with a well placed shot (save for the nameplate which then gets put in the trophy room attached to the thickest and most burnt piece of armour
).
Wouldn't give the weapons special attacks though - probably too much icing on the cake.
Might make them all Independent, I think - simulate their small units acting on their own to secure the worthiest kills.