These are all Formations included in Shield of Baal: Exterminatus. They all have access to the Archangels Warlord Trait Table and Relics.
Archangels Orbital Intervention Force
This is a very straightforward Formation, consisting of any combination of 3 Terminator or Terminator Assault squads. They gain the rule Swift Deployment, so they all have to be held in Deep Strike Reserve and the entire Formation arrives on a single Reserve Roll. When they arrive, the Terminators can Run and then shoot.
This is a very slight benefit, and it only really helps standard Terminators (since Assault Terminators don’t have any guns to shoot). Even so, being able to reposition your deep strikers as well as shoot is a decent bonus. If you want to take a bunch or Terminators but don’t want to be as restricted as the Archangels Strike Force, the Orbital Intervention force doesn’t really have any downsides.
Archangels Sanguine Wing
The Archangels Sanguine Wing consists of 2 Vanguard Veteran squads, a Sternguard Veteran squad, and a Stormraven Gunship. All units must be full size, and the Vanguard Veterans have to have jump packs.
This is a Surgical Strike Force, which means that the Sternguard have to be deployed on the Stormraven and the Vanguard Veterans must arrive by Deep Strike. The whole Formation arrives on a single reserve roll, which you get to re-roll. However, the exciting rule for these guys is 1stCompany Armory. Every Vanguard Veteran can take a power sword or lightning claw for free, and every Sternguard Veteran can take a storm bolter (never) or combi-weapon (always) for free.
If you take all of the free upgrades, you end up with 400 points of free wargear, which seems huge. Honestly, it is, and it makes Vanguard Veterans very competitive with our other Elite assault units. Many players will point out that arriving from Deep Strike isn’t a great way for assault units to arrive. This is true, but the Formation will reliably arrive on Turn 2, so it should have no problem being in assault Turn 3. That doesn’t seem like a massive downside compared to the points you save. There’s nothing stopping the squads from splitting into combat squads, so you can engage a lot of targets with this Formation, and they will be quite difficult to destroy. With every model having an upgraded weapon, even the last stragglers of a squad will be dangerous.
No, I think the main problem here is the models. You will never field that many power weapons, lightning claws, or combi-weapons outside of this formation. I have 30 Vanguard Veterans in my collection, but only 10 power weapons and lightning claws between them. Most players will have to build completely new squads to play this Formation, and these squads will be points prohibitive to use outside of the Formation. For this reason alone, I don’t expect to see this Formation very often.
If you have the models already, give it a go. It seems like a very worthwhile assault force for your army.
Archangels Demi-Company
This Formation requires either a Captain or Chaplain in Terminator armor, 2 Furiosos, and 5 squads of any combination of Terminators, Assault Terminators, Sternguard Veterans, or Vanguard Veterans.
The Demi-Company comes with the same rules as the Archangels Detachment, Lord of Hosts (re-roll on Warlord Table) and Storm of Angels(re-roll reserve rolls and Deep Strike scatter D6” less). In addition, the entire Formation is Stubborn.
Stubborn is a decent bonus. If you were planning on fielding an Archangels force of this size, then consider fitting it into this Formation. It’s too large a detachment to slot into most armies, and doesn’t bring any game-changing rules (like the Angel’s Fury Spearhead Force).
The Archangels
This is a company level Formation, requiring a Captain and Chaplain in Terminator armor, 4 Furiosos, and 10 squads of any combination of Terminators, Assault Terminators, Sternguard Veterans, or Vanguard Veterans. It’s exactly double the Archangels Demi-Company, which makes complete sense.
In addition to the special rules carried by the Demi-Company, this Formation has Elite Strike Force, allowing you to make Reserve rolls on Turn 1. With Reserve re-rolls, the vast majority of your units should arrive first turn. This allows you to run the army as an excellent alpha strike force, dropping on top of the enemy Turn 1 and wasting no time tearing into them.
I like the rules for this Formation, but it’s a big Formation. Fielding it will be a serious commitment, and it won’t be a tremendously competitive force. I expect it will hold its own and compensate for Terminators’ difficulty closing with the enemy quickly, but I don’t see it dominating its games.