I've now played three war turns. I don't think I will lose count, because they are ridiculous. They are insane combinatoric logistics puzzles that are taking 2-3 hours each.
So, in the turns leading up to this, I was monitoring wetbandit's units in my borders. Every newly-created unit, and every musterable unit that wetbandit couldn't see, would get shuffled down to replace one stationed in a city, and that would get shuffled to another city, and that would get shuffled onto a transport and stowed far enough out in the water that it was hidden. Some units would move 9 tiles southeast along railroads and then move one tile NW at the end, to make it appear they were traveling the other way. And, I didn't try to do everything perfectly - I expect that it would be hard for someone else to keep track of all my troop locations. The goal was just to provide some reasonable doubt. I don't know how much I succeeded but from his garrisons, it didn't look like the attack was anticipated. The turn before I planned to declare war, I closed borders, because I was having to position two big fleets in vision of land units. I can only assume this was a big red flag, and in fact wetbandit did take the next turn to revolt to slavery, but I'm happy with the level of preparedness I faced.
Here is the first turn of war summarized:
My transports effectively followed the blue lines. I had enough destroyers to bomb down 2 cities fully and one a little bit, so I left the southern city (Aroostook, now Vivid) mostly unbombarded, since it had the fewest defenders. Similarly, I had a limited number of bombers since I only got flight a few turns ago, so Aroostook got airstruck a little bit less. Thus, I lost two riflemen attacking it. Every other combat was a cinch.
Here's the full list. You can also see I captured a few workers of wetbandit. They had been scouting around my territory and looking for forests in his culture to chop for his defense against Gawdzak.
Due to the fairly light defenses I faced on the first turn, I had a ton of units that weren't even used yet. Here is the main group of those units, setting up to take the next couple of cities.
And here's the north, where I'm threatening an island city (but didn't have the destroyers+bombers available to make a move on it yet), and next turn will threaten 1-2 more along the coast.
Brief domestic digression. I finished Cristo Redentor the turn before, and with the capture of Shwedagon Paya I can now swap back and forth between theocracy and free religion every two turns. This gives every draftee the extra XP from theo while still giving me the science bonus every other turn. Past that, the civic switching is currently of limited value, though the flexibility is nice. There's not much point to ever leaving representation, nationhood, or mercantilism, and dipping into slavery will have to be very rare because I rely on both parts of caste system. Also, since I completed refrigeration just before the war, I founded Cereal Mills and will be working on spreading it as soon as Broadway is done.
Back to the war, I forgot to take as many screenshots for the second turn, which may have been the longest I've spent on a civ turn so far. But here you can see my conquests.
After capturing the three cities, my problem is the large stack of cavalry sitting in the middle of his core (and the smaller stack in his capital). Luckily for me, I am Russia and my cossacks are really strong against cavalry, so I just piles a bunch of them into Texlahoma aka Acid Bath (had to start a new alphabet of names). I ferried a couple cavalry over to Xbox and cut the roads, put up a strong-enough defense in Yoyo to make it a poor move to attack there, and also cut the road that would allow them to reach Zigzag and Vivid. So now his only way of accomplishing anything with the cavalry is to make a desperate attack on my cossacks, and spoiler alert, +50% is a huge advantage. Still, this is what I was most afraid of, because I didn't calculate his actual odds and because any fight where the opposing units aren't at half health from bombers is to my relative disadvantage. Funny story there: I did have a spare bomber in range of the 19 cavs and attempted to perform an air strike, but I accidentally bombed instead, destroying a windmill. That's why they're on an unimproved tile on that last picture.
Turn three is played as well, but I haven't yet gathered the images for it.