Just as a disclaimer, I hope that we all can consider this to be as good-hearted as Blademaster described.
What I don't get is this assumption that the Knights in Rihad and Roseguard are going to just sit there and wait during the whole siege. There are enough of them to either open a supply line through even County Kvatch or reinforce Terentius' guys. That Anvil claims the Brena River is irrelevant unless they've actually been digging in to prevent the Knights from getting through, and even then it wouldn't be hard to bypass them.
And no, the Knights are not actually the minority. And yes they are strangers to the Confederation, but so are the Yokudans soldiers and nomads. And if anything, the Knights would command much better knowledge of the layout of the city than the invaders and a better rapport with the locals, especially if they have aid from the Taneth militia and city guard. Even if there are Yokudan agents inside the wall, they can't magically give knowledge of the city's layout to the invaders. Assuming they don't get caught and tortured by the Inquisition.
Now, for the record it really bugs me that Sentinel somehow has 18th century cannons that remain a secret recipe from the rest of the world and the recipe can only be found in Hammerfell. It's probably more than anything because I'm butthurt that I've not found a viable excuse to re-introduce steampunk technology into the Timeline. I'll try to keep that out of my arguments. At the Irk Bridge, IB's guys showed that sloped earthen ramparts are not only existent in Tamriel, they're very effective against cannon fire. I think it would be the same at Taneth. It'll be even more effective considering Taneth has mages to counter-bombard the Yokudans artillery or flood fill the ditches with fire. And there are enough mages to rotate just like the cannons and their crews. How long can the Yokudans sit there while fire is raining down on them? How long can they sit while they're drenched by a monsoon while their soaked cannons sink into mud (I figure if the Psijics can summon a storm to sink a fleet, enough lesser mages can summon rain)?
I think it'd be cool to have the mini Imperial City RP going on while the Knights and Yokudans are still fighting in Hammerfell, rather than after it's resolved. One of the immediate issues could be the war: should Cyrodiil pressure the Knights to withdraw, or could they take advantage of the conflict to annex the Confederation (which I wouldn't put Terentius past promising in exchange for aid)? They'd gain both Taneth's and Rihad's treasuries and gain a port city on the west coast. And they know that the Knights wouldn't dare oppose them.
I think this RP was doomed to fall into arguing by the very thing that kept it going for so long: it was free form, non-linear, very wide open, and pitted RPer against RPer. It pitted pet faction against pet faction, with both sides scrambling to appeal to the rule of awesome and the rule of cool and most importantly, not get wiped out. Unfortunately, when it comes to its logical conclusion there will be hurt feelings.
I liked Circlet Ignited too, but I fear that had it continued on as long as KSS, it would have eventually created conflict as opposing sides oppose and thwart each other's machinations.