I also do not like the current system of having this faceless,nameless, and personality-less commander as some people have pointed out already. I would like that you could customize one or all of your brothers at the start. Then have them or whoever you selected start out as the commander who represents your party on the world map/quests/events.
Obviously you would not want their death to be game over. Instead you could choose who the successor be, or have them elected from your brothers based on: who’s been around the longest, the brother with most experience, traits, or some combination of all them.