Firstly, regarding the Cooperation option - I would say it's solidly the second best option, but just because Ulthuan coughs up the Waystone knowledge doesn't mean it will be actually usable in the immediate term. If anything, it's probably based on High Magic, which no one but them can use. I've no doubt it will be valuable in terms of magical scholarship regardless, but still - it will be one more research option that only a handful of people in the Empire are qualified or have the clearance to work on. Don't get me wrong, more Waystone knowledge is good - but Eltharion is literally here because what we have is already good enough for government work. Hell, we might even figure out how to connect our Waystones to the network by ourselves - we don't actually know that we need Ulthuan for that.
I don't necessarily think we've hit the point of diminishing returns, but what we'd be giving up in opportunity cost is enormous - Marienburg.
I'd like to make an argument for Marienburg being possibly the most geopolitically important advantage we can secure, and the best option, and why. I'm not in this just for the 'fuck Marienburg meme' - Marienburg is legitimately a lynchpin that will immediately benefit the Empire and allow us to start kicking Chaos directly in the teeth.
PLAN: THE MARIENBURG CONNECTION
[ ] [ULTHUAN] Marienburg
While this matter alone is not enough to pry Marienburg and Ulthuan entirely apart, concessions could be extracted that would be advantageous for all of the polities involved in the Waystone Project, such as the free flow of trade from the Reik to the Sea of Claws, and an explicit stance from Ulthuan regarding the canal matter instead of their current deliberate ambiguity.
Important parts bolded and underlined. As a refresher,
here is a link to how important Marienburg is by word of Boney himself, but I'll quote here anyway:
Point One of modern Empire Naval Policy: Fuck Marienburg
How much coastline does the Empire have? Less than any non-Dwarven polity on the planet. Why? Because Marienburg took two thirds of the coastline when it seceded. See Point One.
How many significant towns does the Empire have on that coastline? Only one. Why? Because Marienburg sabotaged the other two towns that the Empire tried to establish on it. See Point One.
Is that one town at all vulnerable? No, because half the fleet is based there because there's only two places in the Empire that can actually maintain seagoing vessels any more because most of that infrastructure was in Marienburg. See Point One.
How much naval force projection does the Empire try to do? Not much, because the other half of the fleet is based in Altdorf and has to pay ruinous tolls to get out to sea. See Point One.
How much naval trade does the Empire try to do? See above, and then see Point One.
So, do the Druchii connect to the Empire's foreign policy in any other way? Well, they're infamously opposed to the Asur, whose involvement in the Old World involves sending three dudes to protect the Old World against the Everchosen and then sending a fuckload more dudes to help slaughter an Imperial Army in the Battle of Grootscher Marsh to support Marienburg's secession. See Point One.
Which is particularly prominent in a lot of minds currently, because the only reason Marienburg feels confident to threaten a full blockade of the Empire in response to the canals is because of the continued protection of the Asur. Which also means that in a lot of minds right now, Point One of Empire Naval Policy is echoing very loudly.
Which means that right now a concussed toddler could make major diplomatic inroads on behalf of Naggaroth if you could teach it to reliably babble those five syllables in the correct order.
Marienburg. The one former elector province of the entire Empire, single-handedly impoverishing the rest by forcing them to either pay their tolls or enormous transit fees on merchant trains to the other realms of Order. If you want to know how important it is, look at just recently when they had to root a full fledged Chaos cult out of one of the ruling families.
If you want to know how important any step towards getting that stranglehold off is - the Empire literally started entertaining overtures from elves who worship rapine, slavery and murder on the mere suggestion they might be able to undo it. If you all were one of the users in thread aghast at that, consider the idea that taking the Marienburg Option here more or less kills that seed of bad idea right here in the cradle by taking it off the table for the Dark Elves.
With assurance of trade and the canal in our favor, we open up unprecedented arteries of trade and navigation in both the north and south of the Empire. The benefits of the southern one is already known - the Karaz Ankor and Karak Eight Peaks newly connected to the Old World and Empire once more.
Marienburg, meanwhile, is enormously rich off just 60 years of separation and gigatolls from the Empire, which is part of what makes them able to stay seceded. Sure, stopping them now doesn't take that wealth away - but it does take their wealth growth from exponential to merely linear.
Opening up our passage through Marienburg lets us get the Imperial Fleet out from Altdorf to start kicking in Norscan doors on the northern shore of the Sea of Claws, which allows us an actual hope of recolonizing and controlling that coastline and making Empire naval power anything but the punchline of a joke. Hell, if you ever wanted to go see if the Norse Dwarves are still kicking, allowing naval passage is the way to do it.
Getting us access again to the Sea of Claws has specific, measurable, tangible benefits for the Empire, Kislev (in having the Imperial Fleet, which they already rely on, even more available), and the Dwarves and Laurelorn (same reason). In all likelihood, it is what the Emperor would want out of this. No, it doesn't bring Marienburg back now, or even separate the Asur from them yet - but we might never have Ulthuan over a barrel like this again.
And for those who like favors - this is the kind of great act that lays the groundwork for Mandred as the first Wizard Emperor, same as Bokha. And if this actually ends up being the first step to bringing Marienburg back in, they might make Mathilde it's Elector Count and I am being so serious when I say so. Who here
wouldn't like to open up the
North Imperial Company?