Empire Campaign with the Marienburg mod and the Elector Count mod feels so fucking good. Feels like an actual loreful Empire. Marienburg keeps their trade route mechanic from the mod even when confederated so you get to actually do the trade with other powers that the Empire does in lore, each Elector has a unique playstyle he best works with and some of them even have attached heroes and champions from the lore, bringing together the Empire feels like an actual worthwhile undertaking, its great. The only issue is being surrounded by so many concurrent allies 'helping' you with your wars is a problem.
I was able to take the Black Pit for the Bretonnians and trade it to them for the parts of Middenland they'd taken (though they later lost it to Skattach and I took it lol) and Karak Ziflin actually moved to help me and took some of Middenland as well but I was able to trade them the Brass Keep which was great to have them there helping me, but then they took Wolfenburg and there was no settlement under my control I could trade to get it back, so I ended up having to go to war with them, which sucks. I'm hoping they stay alive in the Brass Keep long enough to peace out with me and we can be friends again, but Louen already took their homeland in the Grey Mountains on my behalf which kinda sucks.
I really wish there was a way for Order factions to "request" land from their allies that is legitimately theirs without having to either happen to have a good trade lined up or just killing them. The Wood Elves have this same problem with Bretonnia always having to fight them in order to take Parravron and sometimes Carcassone back when they (always) steal it. Its a pain in the ass. I wanna fight Chaos and Greenskins, not my Short King bros.
(unrelated pic of me taking Lyonnesse from Mallobaude and his diseased peasants and undead knights so I can sell it to Louen)