So far all the Total War fans seem to like this game, so I'm happy it succeeded in that regard! I'm honestly also surprised it worked out as well as it did, since I've never done anything close to this before.
You're absolutely right about the difficulty being too low, and that was intentional. The players units are almost across the board a step above the Saxon soldiers, in fact if you double-click on the enemy unit banners you can even see the difference in stats. This was because I figured very few people in the jam would be familiar with the Total War franchise (though so far there's more than I expected), and I wanted anyone who honestly tried the game to be able to win. I had issues with my last game being so difficult a few people couldn't make it to the end, so I didn't want a repeat of that. The cavalry I specifically buffed so that players who were not great at micromanaging and cycle-charging could still keep them alive. If this were for a non-jam game, or if I had more time to add mechanics and balance values then I would definitely make the game more challenging.
I was actually going to make an intro cutscene for the battle but didn't have time to do so, so I'm happy the lore dump was sufficient!
The unit placement I actually relied quite heavily on a tutorial project by Jonas Mun, so all the credit goes to him for figuring out how to drag out formations and for being able to pivot the drag around a point. But I did have to sort out how to make units move to the destinations, and to break out that functionality so it would work on any units selected rather than just have one rigidly defined selection. I'll likely write up more on what I had to do after the jam.
Thanks for playing, and for the feedback!