Question about Military Leaders

[SeraDC]

Hi all,
i got a question about military leaders. How does the game decide which military leader takes command in a fight?
I have this really huge fight with over 50k soldiers on each side and i am bringing a 5/4/3/1 and a 3/2/6/1 Conquistador to the fight as Spain. Now Burgundy joins in on my side with a 1/0/2/4 Heir as their Commander now this guy takes over for us with clearly the worst skills in combat. So how is this working exactly?
Before he joined the 5/4/3/1 had the command but now ... Now Austria my enemy has +3 in both phases were before this they had -1 in both phases.
I just want to know how the game decides who is the leader

 

[Stategem161803]

I believe rulers > heirs > generals. All else being equal, the game selects the leader with the best stats. In your case, burgundy's heir "outranks" everyone else and therefore takes command. This is particularly annoying when a vassal ruler take over command of his liege's army.

 

[Cavalry]

And I think "best stats" leader is the leader with the most pip. Some time your siege/maneuver specialist take over the fire from your fire/shock general.