[Mightypeon]

I this war, I also a significant number of spies operating in Pythium which were busily reducing income in a decentralized manner.

A fairly important part in all this was my cunning trick with secretly allying with Mictlan(who you were conquering), while preparing a gigantic trap at mictlans Capital. Given that I moved on Mictlan after you asked me to do, while actually being in collusion with them, I managed to inflict a very severe first strike with that Earth Quake attack. If Mictlan wouldnt have been sleeping, it would have wiped out most of your standing army in the inital turns of war.
This did allow me to seize the initiave, and rapidly conquer former Mictlan (with some help from Mictlan itself, although I could argue that they were more of a hindrance, As Napoleon said, fighting a coalition is often easier than being in one). You had to recruit new troops and rush those to the front, which preempted any coordinated action against my Spy Corp. In the opening moves, I seized a significant advantadge in money income which became greater as overtaxing and induce unrest succesfully destroyed Pythiums economic basis.
The whole build up to the war as quite important as I could, and did, plan my force composition about 3 to 5 turns in advance, I later discovered that getting armies in place while being raided by harbingers is quite difficult. Ulm can only recruit its troops in its own castles (as you need high scales and your own dominion for castles to be productive), and they are still Map move one for the most part, although I was makig large use of knights and Sappers for strategic mobility.
I was quite amazed at how shockingly effective Ulms troops are when fighting Pythium too. In the early turns of the war, I had Pythiums mainly mage less army, with still 300ish Principes, encircled in Mictlan. Since Sallying forth happens last, I was moving my surrounding armies into Mictlan in order to prevent Pythium from getting away.
To my suprise (my goal was to stop them from moving), my 80ish black plates with I think 12 Mages totally and utterly murdered the principes suffering only very slight casulties, and, despite having no gems left, inflicted severe casulties on Mictlans sallying army too.
In this battle, I was using the MR and the Armour buff, further increasign S with strength of giants and otherwise relyign on destruction and Iron Blizzard. I had nearly no casulties from Principes, and these not exactly bad troops more or less melted upon impact.
Basically, if you use destruction in tandem with Flail troops that have strength of giants on them, everything with destroyed armour instantly dies upon getting in combat.