Aright. My 2 cents.
Leadership [skill] as name suggests should be charisma affected if we look at various RPG systems. IRL It's the ability Joan of Arch for example displayed. Having little to no military rank, affecting soldiers in the field. Or William Wallas. A clansman, not even leader of his clan becoming a leader of a revolution.
On the other hand, Tribunal [aka Military structure] should be level based.
Guard will have to obey the commands of his Tribunal Leaders and members. For members lets say level represents rank as an easy way to do it.
High level guard, Lieutenant, Captain should be more difficult to order. A leader should definitely obey the commands of a trib leader. Look at the oaths the Tribunals have when entering, which are Military oriented.
Solution? Rename Leadership skill for Tribunals to Rank or something of the sort. Like mentioned before, charisma already affects a variety of other factors. I cant see why i could not order a guard to come with me when X enemy is slaughtering the guards and people of my city, simply because i am a [priest] and i have prioritized in Wis Int Art Mana for example. I won't hide this played some role in the fact that my current char not entering a Tribunal so far.
Again, this sounds like a touch change, I'm not holding my breath.