Blake wrote:
Sounds like lots of progress was made, so is there a large variety in the types of units the Sorceria Guardians are able to build?
Not really. The Sorceria Guardians don't have a huge variety; they are rather overpowered in general (they use Ancestral Spirit on each other, for instance). All their units are reskinned Naga and they use the flying dragons in Book 4 as air units.
The West District, so far, is the one district where you generally get to fight them. The other districts have different flavors; the South District primary enemies are the Burning Legion and the North District primary enemies are the Mur'gul (and the Guardians, but it's a fairly Murloc-dominated zone)-- and perhaps Kuth'kullen's Black Moon undead forces as well. The East Distrct has the Guardians in it as well, but it also is being attacked by the Invaders, a new faction of enemy that appeared in the city (they aren't completely unknown to the story, but that's all I'm going to reveal about them for the time being), so I don't know how extensively the Guardians will feature there.
The North District, being Kuth'kullen's former abode, is perhaps the most story-oriented, as there's a huge amount of backstory floating around in here and reveals just what Kuth'kullen was planning to do (or, perhaps, NOT do).