Agreed, the overall UI needs some overlook - especially infight. It takes ages, to get regular troops to high lvl, therefor u really want your units to stay alive.
Unfortunatly, this is quite hard, since once u got more than one squad of a specific unit-type in your army, they start to "share the health bar", what is very unconfortable (and is leading me to NOT have more than one squad of an type per army).
Why dont u keep one portrait of the unit, but put more than one healthBars under it? (ofc, here the healthBars should be clickable) Suddenly, we would have a way smoother armyControl...