I just read the fourth preview and figured there was a lot of info to gather from that one.

The info that especially stood out IMO was the text on the Beastman Special Ability :

http://www.fantasyflightgames.com/ffg_content/runewars/previews/preview4/runewars-neutral-monster-reference-sheet.png

COMMAND : Deal 1 damage and then draw and resolve a new fate card ( limit once per Beastman )

Especially the part between brackets is interesting.

This seems to imply that during combat each Beastman that gets an Orb on its first Fate Card may deal 1 damage and draw one additional Fate Card.

Meaning : in general, in combat , you draw one Fate Card for each (standing) unit. ( which would make most sense IMO )

Or is there any other way you can interpret that Special Ability wording ?

Something else seems to support this theory, the Hit Points of the Dragon and the Giant.

If you're facing a Giant, how in the world are you supposed to take this guy out with an Archer army if you draw only one fate Card for the entire Archer stack ? It's impossible.

If every unit in the stack draws one Fate Card however .... then you may have a shot ( though you might need about 9 Archers to deal statistically 5 damage to the Giant )

This is going in the right direction IMO,

if we now also can have an army size limit to prevent stacks of doom I think this is going to be a super game.

I came to the same conclusion about the Beastman special ability. The only other interpretation is that you can only use it as long as you keep getting orbs as many times as you have Beastmen. Thus, if you have three of them, you could potentially make use of three consecutive orb draws. I don't think that's correct, however, so one card per unit definitely makes sense.

Seems a bit like StarCraft Skirmishes then.

Seem to have hit that one on the head as well