So after a few games with the new faction I can only say WOW THEY ARE FREAKING COOL! Also I have no idea how to use them. They lack the traditional niche units (Tank/Frontline, Antitank, harasser, air fighter, bomber) and all their units are very unique and weird. However, that makes army composition super difficult. My biggest problem with them is the lack of a strong front line. The Klaxon seems far too squishy to be a frontline, but looking at its stats it's comparable to the Goo Destructor and those things just never die. So perhaps it's me using them wrong.
I'm liking this expansion a lot. The Shroud is really a fresh air to the game and the genre in general. It's just...extremely weird to play a faction that has none of the bog-standard type units. Heck, their air-to-air fighter is a kamikaze bomb that can also target ground. Their long-range bomber is a unit transport that uses units for ammo! They're just every kind of weird.
Their strength is easily their numbers. It's super easy to pump out bajillions of light units in a very short time once you get an economy going. Their epic unit is also ridiculus once it gets off the ground. Their anti-air is very strong as they stun airplanes entirely for a duration.
Weaknesses include lack of strong frontline, weak T1 units, lack of in-field stealth detection without upgrades, slow to get off the ground early game and severe lack of great harassment potential early on, leading to a difficult game against Goo. I imagine profilic use of the Supercharger on T1 units and sending out harassment squads would help.
The new faction is indeed very cool.
For better or for worse, the Klaxon is their frontline "tank" unit. Though if you're facing the Goo, it would probably be worth choosing to remove the "charge" ability, and choosing the upgrade to give it more armor when massed. You don't want them 'accidentally' charging into the formless Goo.
Actually, all 3 of the Shroud 'Tier 2' units play the "tank" role in their own way. The Klaxon simply has a lot of health and armor, comparatively. The Echo forces the enemy to focus fire on its attack, within a fairly large radius. The Fugue (this name always makes me think of Breaking Bad lol) creates little units which can act as bullet sponges in a prolonged battle.
So in a way, the Shroud disperse and delineate damage in a unique and tactical manner. In this way they are similar to the Beta, who also doesn't have a particularly suitable "tank" unit. The Predator has decent stats, but is specifically designed to move while firing to avoid taking damage. The Humans had a similar problem, but I have to say that the Valiant has a godlike damage absorption mechanic, even keeping formless Goo out of the bubble.
In terms of how their T1 units compare, I need to do some more testing. They are the only faction that has a basic T1 unit with an aoe attack (Howler), which seems huge in early skirmishes. The armor reduction of the Clasher may be nearly useless in this regard, but no more useless than the armor penetration of the Beta Stalker, the Human Revolver, or the Goo Strider, which all truly begin to shine as the game progresses. The only disadvantage I can see is that the Shroud T1 units seem more expensive, or perhaps they simply take longer to build because of their early-game economic mechanics.