Of course if Ulfric was smart he'd try teaching Shouting to his most loyal men. Takes years to master a shout sure. But if I were him I'd have begun training before challenging Toryg. Of course for whatever reason you never do come across a Stormcloak who is capable of shouting. Which to me feels like 1) Ulfric is just too damn paranoid or 2) He was entirely stupid and forgot this. Again from what I understand Shouting is a skill any Nord can have with the right dedication and training and probably lots and lots of meditation.
Teaching is its own skill. We all have our cliches, but just as we can't all be leaders, we can't all be teachers either.
I have thought of it like The Revolutionary War for The United States, The Stormcloaks are the American Colonies and The Empire is The British. I would also think that Ulfric is a lot like George Washington in the way that everyone looked up to him and was pretty much their leader. Everyone thought the Colonies were going to lose and it was going to be a short war, but look at what happened. I believe The Stormcloaks would win just because of their spirit and determination to get what they want.
Here's the problem: the Stormcloak is a "personality cult", so while it is possible -as I've even argued in this very thread I do believe- for the Stormcloaks to survive without Ulfric, there's a problem with your analogy: George Washington was not anything remotely close to being the only "morale leader" of the Revolutionary War: Thomas Jefferson, Benjamin Franklin, Samuel Adams, Patrick Henry, and Thomas Paine were the far better voices for the war (and they either recognized that the Revolution started in the early 1700s and/or they wanted war sooner than later).
(^Edit: Not to mention, the Revolutionary War was not backed by a personality cult to begin with.)
Let's remover Talos, Ulfric and the killing of Torygg, and get down to the heart of the war. That heart being; Is it right to take away FREEDOM, in favor of SECURITY?
In-game wise: it makes no difference, I'll kill any damned fool that gets in my way.
Realistically: never. Not a single government in history has reverted from security to freedom. Government, once created, only feeds on the security of the weak to destroy the freedom of its undesirables.