Spoiler Thing is though is that no one jumps to help anyone against the dragons. Game mechanics don't define what the characters would actually do if the world wasn't so stiff whenever you weren't actively doing something. And why exactly would a General, nay, the potential High King of Skyrim put himself in harms way? What purpose would it serve at all? None. Tullius doesn't fight on the front lines, so don't hold Ulfric to that end if you don't do so to the other side as well.
And thats not to mention that just because you get your orders from Galmar doesn't mean that the plans themselves didn't come from Ulfric. Its the same thing on the other side of the war. You don't get your orders directly from Tullius
Not sure how much I agree with you on the point of Game Mechanics... game mechanics should absolutely define the character, further scripted actions are seen in the game, these could be put in to define characters, and absolutely Should be used to define characters.
And also, Tullius was actually there fighting. If you listen after you fall out of the tower you were in, when you run into Ulfric, if you went with the Stormcloak guy, you can hear Tullius directing his troops while Alduin attacked.
You do have a bit of a point when it comes to getting orders from the seconds in the game, and not the main leader... But, we hear Ulfric arguing on multiple occasions with Galmar over how things should go. Often Galmar is the one who wins out. This makes me wonder who is wearing the pants in that bromance. Ulfric might have been the one who encouraged this whole mess, but I don't know how much input he's really got is what I'm saying. Tullius doesn't understand these weird north people, so him bowing to a local makes sense. Galmar and Ulfric... yeah, it's a bit more interesting.
Further, it's rare for rulers to lead their armies in person, yes: But, we're asking just how awesome Ulfric really is. He could be the political figure here, and thus he isn't as amazing as people say. Thats what my interpretation is... I found Ulfric to be kind of a [censored] for those reasons.