So I played three two full games the Wizard and Tyrant. I played about half with the Guardian and then stopped because I'd been playing too much.

First, it encouraging to see that you are taking feedback and good ideas. It's why I'm posting.

Wizard: After playing the other two factions, I can tell you that the Wizard is pretty comparibly boring. Besides the spell that takes -25 doomclock for 100 mana, the Wizard doesn't do anything special. I didn't really summon better or cast spell better. I just got that spell and that's about it. I don't remember the sovereign abilities but that because that weren't anything special. Tanis is pretty kick butt once he gets maul. (minor concern, it was impossible to get that hunter weapon the whole game) The one thing I feel about wizards is that in DnD, the Wizard was the expert on most everything but not the best at focusing on specialty. The wizard should have access to a ton of spells and great mana generation, but have weak units that absolutely need spells: summons, enchantments, and evocations (fireballs). I don't know why Wizard has access to Paladin or units that feel something a king would have. Wizards have magical beasts. Also, battlemages need to be more powerful. I also like the hypnosis ability but it was resisted more than I felt it should. That's my thought on that. 

Tyrant: I like the hero unit even though I slaughtered everything with his attack everyone ability by the end of the game. I tried to play evil and it was a fun roleplay and I loved that the doomclock actually helped me become more powerful. That's pretty cool to be Sauron to the Sorcerer King's Morgoth. The concept is excellent. I would again love to not see Paladins and some of the units I would associate with a kingdom type. As far as the Tyrant concept, I see weak, cheap units that aren't that tough but are cheap and easy to summon. He might have evil paladins or evil this or that but very little healing involved. Another thing, I loved to see the Tyrant be able to use that Sorcerer King land. 

Guardian: I didn't get as far with this one but it certainly played differently. I like that the tower have a significant zone of control size improvement. It made towers especially useful. I like that he had an easier time getting loot but I couldn't make a bow to save my life and the main hero couldn't use his area of attack ability with a sword equipped. I do like that there are ability to modify the world around him but it feels like those should be spells that only the Guardian can research. Also, archers as a unit are exceptionally underwhelming and underpowered. I like the sovereign pathways though which give archer first attack. (it seemed like they lost their first move because of that though). As far as concept, I see the Guardian as weak melee units with good range (non-magic) with access to good units.

More thoughts and experiences:

1. Sometimes, and I couldn't reduplicate it, when the towers attacked, the game would sometimes freeze and crash. It didn't happen most of the time.

2. Buildings are pretty boring since there isn't much diversity between factions. THe production and food buildings are fine though. I don't really mind that I don't see what's being built like Fallen Enchantress.

3. There needs to be a way to track food more easily. That system is a little too obtuse. I found it eventually but it a tooltip over food or clear graphic would help.

4. There needs to be more logistics (especially with the towers needing logistics change). I never never never had more than one army. I pretty much depended on one doomstack to do everything.

5. I wish everyone started with build road spell or that pioneers could build roads too. (I don't mean outposts for roads). It was too hard to get around the map (except as Tyrant when I had a 9 move by the end of the game)

6. I played one game where I boxed in the sorceror king (as the Tyrant) with upgraded towers. His units never attacked my tower and took it out. Instead there were stacks of 20 wandering around when I finally went down there. It was good xp.

7. As far as towers go, it was not immediately clear that a pioneer needed to be built and sent to a tower to upgrade it. I preferred the Fallen Enchantress method with the closest city building the upgrades.

8. There is too much micromanagement with items. Leveling should mean a lot more for defense for units like Riders or Paladins. Again, the Fallen Enchantress method were gold could be use to update the armor would be nice. At the same time, I really do like equipping my units, I just never did it because I didn't have enough material to properly equip my army. If cheap armor was easier to get then it be nice. The easiest solution would be to just have a weapon, armor, and ring slot for basic units.

9. Auto-resolve AI in battle was incredibly stupid and I wish there was a method to make AI not spend mana. Auto-resolve before battle even starts was even sillier and lost me a lot of HP until I stopped using it. AI did not often choose best attacks even if it didn't cost mana. I wish I understood why I auto-killed some units and not others. It was not at all clear. I'm glad for that feature though since it helped avoid some annoying battles.

10. Sovereign King units seemed to spawn from nowhere. It wasn't clear how the Sovereign King was able to spawn so many units. I know the SK is supposed to spawn lots of units but I wasn't sure it those units came from the SK's castle or those rocky formations that I tried clearing. It seemed like a darkling army would spawn every few turns or maybe it was six from one place. I just wasn't sure. In Civ4/5, I was always sure that the computer spawns units from this or that city more or less.

11. I wish the Sovereign King land would fade away over time or perhaps able to be changed by pioneer if area is controlled. 

12. Itemization sure needs help but that isn't surprising. The one thing that would help a lot is being able to see what I could craft if I had this or that material. The items would only show up if I got the items. I'd be nice if I could purposely go to a certain terrain knowing I might get x or y material. 

13. The minor factions were confusing at first. The SK always slaughtered all of them without them giving any fight. They need more unit and more powerful units. I'd love to see them have as good a chance to "win" the game like me. I also never was able to finish a quest from any of them. The quests were often too unclear. Though to be fair, the greater issue is that I'd get a quest and then they'd get their capital taken and then want to eat me.

14. I enjoyed the game and look forward to what it'll be at release and the future.