I also didn't watch to the end. Who cares what happened if AI cast Arrow Fend instead of Mass Flight? Now let's imagine that AI did what I asked him for. Can you predict the results?
I already ran into the same s**t once but after that it was told that devs got rid of this Arrow-Fend-high-priority bug, but... This battle was not my mistake and that's what makes it so disappointing.
Frankly speaking, I am EXTREMELY tired of this game and dominions altogether atm. Yes, my empire is huge, it's nearly enormous and the hordes of undead I generate can now be compared to Ermorian, not even mentioning tons of gems, tarts, wishes and other tasty stuff.
All this is cool but I am too busy at work and real life now and have no time (and wish) to spend on dominions. I turned my nation into a monster but it is so hard to maintain this monster that it leads to a sad conclusion: the better you play the harder it is to keep playing.
All that said, I am very close to suggesting both you and Caelum (of course) a draw. I doubt that an adequate sub can be found for 100-province empire so that's probably the only option aside of continuing.