To say that it is lightweight would imply that it offers inferior protection to the Mks preceding and following it when that is not the case. However you are correct in that it is lighter than its predecessors and the most stealthy however considering the very close ties between the MK VI and the MK VII it is not unreasonable to assume that the Aquila pattern suffers little to no loss of these stealth capabilities. Both marks of Armour being able to enter a "silent running" mode wherein all nonessential systems shut down to dramatically reduce heat and noise creation. While this does render the armour largely inert it can be reactivated at a moments notice and Marines do not suffer a drastic loss of performance when their suit is powered down anyway. Also the Raven Guard were the pioneers of the MK VI armour hence the Corvus designation in honour of their Primarch.
At the end of the day the game must specialize in certain areas, yes everyone should have the option of being able to do almost everything in the game but each choice should come with specialized equipment and requisition of resources. You want to stealth you use scout armour (and then have the weapon benefits and limits that come with it, you want to go assault you pay for a jump pack or bike, you want heavy weapons you need to be wearing power armour or you should be limited to 2 man weapon teams like the IG. The unit's skills should be learnt through a skill tree, different types of armour grey the use of different skill out ad come with different weapons options. The game shouldn't limit players but it should enforce role choices at least in the short term (which role you selected for a specific battle).
Otherwise I'm thinking of abominations like an assault marine on a war bike, blasting his enemies, ditching the bike to jump pack over an area of impassible terrain, landing in cover and going stealth only to sneak forward to a point where his enemy is vulnerable and pulling out his heavy bolter or missile launcher.... No thanks.
The Idea of Stealth has been on my Mind being iam a Nightlord And its something my Leagion is Good at But i have to agree The whole Invisable thing is Mutch . BUT That does not mean stealth still cant be added Things Like Raidar Jammers for your power suits could still be imployed Consealing your movements. And possibly Vox Jammers(thow Doubtly) It would be Nice to Jam enamys Calls for help Singleing out Small Squads For Ambuseing
I'm definitely with you there. I'd like people to have areas they're good at and kind of stick with them. Nothing wrong with being a devastator just because you like devastators or whatever. It's just more ergonomic in a war effort to have specialized troops available. There will obviously be that group of people who have advanced all of the classes so far and can be competent in any situation. Hopefully we can also have specialists. Like one person who is really good at only scouting and devastator, or even only scouting. That way we have versatility as well as specialization. Incorporating something like Eldar paths would be cool too. Like a tactical who progressed pretty far into the scout tree would get minor stealth skills, or if they progressed into assault a lot then they'd get bonuses to melee. Then people could really hone their play style.
Stealth units could be as simple as a unit that doesn't show up on any form of radar or mini map and is "invisible" if in cover unless you are within 30 feet (grenade range). I have no issue with not be able to see my enemies if they are infiltrating, I have a problem with an enemy that pops up in front of me in melee range, or can make a melee attack before I notice him/her. That sort of action is for Imperial Assassins not marine scouts.
Which would be in rare cases so I'd be cool with it. Circle around, keeping thirty feet away, to where you can come up behind. You'd still show up on radar but you'd have a definite advantage having surprise on your side. You'd have to find a lone player or a group all facing one direction. I could see this working with pincer attacks or stuff like that. Seems doable. I think grenade range is a fair distance. Then infiltrators won't all be super far away. Sniper rifles should need bracing or take penalties.
So long as you're not invisible, even if you are soundless, that's fine as I should have several members of my unit on point waiting for such attacks.