Balgruuf says something akin to "If Ulfric wants to challenge me in the old ways so be it, but I suspect he'll send his stormcloaks instead." I'm guessing you did miss that line. Ulfric didn't have to take Whiterun at all the city refused the Empires offer to garrison troops until Ulfric threatened it with invasion. He simply could have ignored Whiterun and gone after all the other holds.
No, now that you quote it I do remember him saying that. The question I'm asking myself is, why would he even bring that up as a possible option? Is he really that obtuse? The "problem" of Whiterun with regard to the CW requires a military solution. That's as true for Tullius as it is for Ulfric. That is why an actual battle is inevitable. A duel between the Jarls would be one arising from personal animus between them, and if that exists at all (which I don't think it does on Ulfric's part) it's irrelevant here from Ulfric's standpoint.
Both Tullius and Ulfric consider Whiterun vital because of its location and gaining control of it is the next logical step in their respective military campaigns... in fact Tullius is so determined to get troops into Whiterun that he's willing to lie to Balgruuf about the situation before Ulfric has even made a move in that direction. Whiterun cannot simply be ignored because neither side can afford the risk of having Balgruuf suddenly decide to throw his lot in with the enemy, or with the enemy occupying such a strategically important territory by force while they're busy securing other holds.
Whether or not you agree with them, Ulfric had reasons for challenging Torygg to a duel. Those reasons don't apply here. He doesn't want to be Jarl of Whiterun, he doesn't need to make a point about Balgruuf's abilities as a ruler. The goal is to control the territory, and while removing the current Jarl may be necessary to that end, it's only necessary because Balgruuf makes it so.
Why he even brings up the idea of a one on one duel... that just seems to stem from Balgruuf's personal animosity IMO. Clearly he doesn't like Ulfric, and I'm willing to bet that was a fact long before the death of Torygg. Maybe he'd like a chance to duke it out with him personally, but that would have nothing to do with the fate of Whiterun. Why would Ulfric want to challenge him in the old way over Whiterun? It's ridiculous to even think that IMO. He has no reason to, and it would solve nothing. As I've already said, even if Ulfric got control of Whiterun that way, he'd have no reason to expect the Empire and their representatives to accept that, he'd have to fight a battle to occupy the hold anyway. Without the Stormcloak military already controlling the territory, if he dueled Balgruuf and won it would just be Solitude all over again and he'd be branded a murderer by the Empire for the second time. Once they do control it, that's all they need and any personal animosity that exists between them is irrelevant to the situation.
People talk about Ulfric's honorable duel but there is zero evidence it was legal.
If the duel itself was illegal, then Ulfric should have been arrested for issuing the challenge, and Torygg should have been arrested for accepting it. It should never have been allowed to take place. Obviously it either wasn't illegal, or the decision of the High King to allow it took precedence over any existing law that might forbid it. If it was illegal under the laws of the Empire, then it was a law that Torygg willingly broke to his own detriment and he should not be portrayed as the innocent victim of cold-blooded murder.
If the outcome of the duel is not "legal" in the sense of being a valid claim to the High throne, then that would be a matter for the moot to decide, not the Empire.
ing about the Empire instead of puting the blame on the Thalmor was more important.
I don't think we can assume Ulfric has been Jarl for "decades." It's only been 25 years since the Markarth Incident, and he went to prison after that. I have seen nothing that says how long he was there. He could have been Jarl for two decades or less than one. Either way, like any leader he has priorities. Not everybody agrees with them, such is life. You cannot assume that his reason for keeping the Argonians out of the city was any different than Brunwulf's, nor can you assume that he would not work to change things the same way Brunwulf claims he will once the time, money, and resources are there, because you can't prove a negative.
And even after Ulfric takes over the Thalmor Embassy stays standing so does Northwatch Keep if he's so ready to fight the Thalmor why doesn't he strike those locations. Could it be that he's really a coward and knows Skyrim would lose that war? or is it because this is a video game and massive world changes would be incredibly problamatic.
He doesn't strike those locations because the devs didn't want to deal with players screaming bloody murder because they finished the war for the Stormcloaks first and then found out that other quests, including the Main Quest, were irretrievably broken because the Stormcloaks went to the specified locations and killed all the Thalmor there.
