Hero skills
Leadership skill - This seems to only apply to the hero that has that skill, and not the whole attacking group. I think this skill should apply to the whole attacking group if a hero has it, or removed and just added to the normal leader stats for that hero.
Other stats with similar issues.
Attack power skill - Just up the attack power of that hero.
Defense - Just up the defense stat for that hero.
Marching speed - Add that to the speed of the hero.
I think these should apply to the whole attacking group, and not just the troops that hero is commanding. Otherwise, why not just increase the stats of the hero?