(edited)
I have not been able to play this yet - I have warband 1.32 and this mod and my install seems to not get along very well.
However, I must admit it seems to be a very interesting mod, not the least because of the backstory. I can't help thinking someone's been playing Empire: Total War, though.
About artillery - if it ever makes its way in (both catapults, ballista, cannons and other types) I increasingly imagine the Lion Throne would have bombards; the Imperial State would have something more akin to regular 18th century field cannons.
(I kind of think of the Imperial State as something more similar to 18th century Prussia, the Lion Throne as the earlier Holy Roman Empire or even the Byzantine / Eastern Roman Emprie.. not sure if that's accurate, most likely not.).
At around the 15th century, cannons were newish (1350 or so saw the first cannons, but they only surpassed older siege weapons in 15th century-ish times) weapons with a large penis comparison factor. States wanted the biggest and the baddest cannons, so several countries had supercannon projects. They are not that impressive by today's standards - modern(ish) examples would be 'Schwerer Gustav', a 1350 ton monster firing 7 - ton shells up to 37 km. (German railway siege gun from WW2), or the gun turrets of Yamamoto (each weighed 2510 tons - as much as a fully loaded fletcher class destroyer).
(It might be tempting to mention nuke cannons but they're actually quite small by comparison).
Right. Back to bombards.
(This is condensed from wikipedia, of course)
Basically, some of the biggest bombards of the time were hungarian (Made by a genius engineer, Orban), 26 feet long, weighed 20 tons, fired a 1200 pound stone cannonball, required a crew of 200 to operate, and transporting it took 10000 men and 70 oxen.... and the byzantine empire couldn't afford them. (They were gifted them to fight against the Ottomans.). Basically, these cannons were massive undertakings, both in engineering and manpower, and could bankrupt even the larger empires of the time.
From its description it sounds like the Aurora cannon was made as a one-time project, and not be mobile.. that sounds slightly insane, but on the other hand, I guess it would work as a demonstration of the Throne's displeasure. It might be like the dardanelle cannon, transported in pieces, then to be assembled and disassembled for use. (That would make the most sense). Then again, from FuryFire's desscription, this is SteamPunk DeathStar. This would be something more akin to Saddam Hussein's Babylon project - which never got close to completion - or the HDP / V-3 project in Nazi germany, which the smaller versions of which had about 100 km range. (The full scale ones, designed to bombard London from France, was never completed. (They were bombed by aircraft, ironically enough).
As an in-game design, if it ever came to that, I'm guessing something akin to Dora might be a good idea; it looks suitably intimidating, if a bit small. Just remove the railway, make it wider, and add steampunk;
But that's also a reasonable explanation for why the Lion Throne is the only nation that has them - the other nations simply are not going to spend their entire wealth on one showpiece, instead of fifty? Five hundred? perfectly workable field cannons that will be vastly more decisive in a battle. Most nations ARE sane. Really. (Well, these ones are a bit too warmongering, but still...)
Anyway, that's just thinking aloud on the subject. I have not read enough of the background stuff so I really may be making wrong assumptions here, but I wouldn't mind feedback on wether I'm on the right track.