You can be terse and/or clear, and still have nobody listen to you.
I was simply suggesting that part of Diplomacy is getting people to listen. It's getting people to think, at least for the moment, that what you're saying sounds like a good idea, that it makes sense.
And, as you point out, leadership in peace time an be quite different from leadership in a time of war or emergency.
Just as Perform can be singing, oratory, dance, a musical instrument, theatrics, etc, couldn't we see different flavors to Diplomacy and Intimidate? Diplomacy would be the fall back for non-military leadership, and Intimidate the fall back for emergency situations.
Normal Intimidation includes some threat or duress, either implied or very specific. In an emergency/combat situation, it is the situation itself that provides the threat, and the Leader who is, at least implicitly, offering a way to lessen it.
I know that they aren't a perfect fit. But they can be used as a starting point.
<EDIT> Or maybe I hit on the answer and passed it by: Could leadership be an aspect of Perform: Oratory? The ability to give a rousing speech should not be underestimated. So how about Perform: Leadership? Literally, "Acting Commander"?

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