@Nevar
That`s not the case (at least i remember from AP/CW was different). Spirit axes do dmg , and then % of it use to heal your units. If you have : shaman , orc veterans , orc hunters , red and black dragon in your army (this is just example) , dmg dome by axes is 2000 - heal will be 80% = 1600HP. That will equal spread among your troops (5x320 HP) but since max hp that could be given to shaman and other orc troops is 397 (if they all are on 1HP) rest of it goes to dragons and heal (2x600 minimum, or if reds are at full HP, then black will get 999HP heal max). This could go a bit more complicated if you have peacefulness on some of troops.
Spirit axes will heal your units to max hp available, but not resurrect them. So it`s not that in mine expl each unit get 320 hp heal, but in case of orc troops they get healed to full hp and rest just dissapaer.

Ah, I see. For some reason I was under the impression it was a 50% heal spread evenly. That makes a lot more sense and makes me want to pick up some shamans right now. Thanks for clearing that up.