There will be horse cavalry. Hopefully there will also be rare Dragonfly cavalry, and even more rare Wyvern cavalry. Even the odd Champion or Sovereign riding an Umberdroth (likely accompanied by several lesser Umberdrtoh).
Sions will allow magical support, at least for certain powerful Fallen Sovereigns.
It would be nice to be able to attach a medical kit to certain units. Perhaps medical kits should be more expensive than their effectiveness, and grant a Radius of coverage, so as to decrease Med-Kit spam?
It would also be nice for units to be able to carry more than one weapon (but only use one at a time) ... think Pavise Crossbowmen.
It would also be nice to have Combat Engineers, like Sappers, and Seige constructors. With the ability to make those things that stick in Cavarly Hooves, like anti-cavalry barriers (essentially slows down cavalry that run over it, reducing their charge and a small chance for the Horse, whom is in pain, to break discipline and run bezerk). In addition, Sappers could dig underneath walls, in order to collapse a certain portion of a wall. Seige constructors could build Basic Seige Weaponry on-site during a proper Seige, so that Battering Rams, Ladders, and Seige Towers could always be rebuilt for sucessive City Attack attempts, if regular Seige weaponry was not built.
It would also be nice to have Ninja packs (seriously) to make having the army hidden be more likely, and to be able to be even MORE hidden while setting an ambush, and giving better ambush bonuses.