I remembered the old game Conquest Frontier Wars and in particular the use of commanders in that game. You can recruit a certain number of commanders and when they die they are lost forever.

Imagine you have a group of units grouped together and when they go into battle their fire will be unfocused, not picking their targets optimally.

In comes the commander, when you add him to a group he will take station in the strongest ship, making a military flagship of it (by title). The effect the commander has to the group is that he make the group pick more strategically correct targets, focus their fire, and so on. He will send ships to repair and all logical things a commander would do.

If the commander ship is destroyed he will move on to another suitable ship. When he is between ships he is in a much smaller shuttle, highly vulnerable to damage. If the shuttle is destroyed or the last ship in the fleet is destroyed the commander is also killed and can not be respawned ever again.

Different commanders can have different attributes and so on.

I think this could add a great touch of personality to the game. I know it's late to suggest but it's worth thinking about and perhaps added in a mod or a patch. Cheers for now.