idea - Can you please setup that the equipment, armour and weapons for hero units cost resources as well as gildar?  This might make it more restrictive when equipping heroes in the field?

From what I've seen it only cots cash to buy the latest and greatest armour etc when tech is researched.  Unless I missed something.  Also if rarer resources are added to the game them maybe only 1-2 heroes could be outfitted which would limit a stack of doom's power a little.  EWOM had elementium that was rare and added some flavor to the map & game.