Finally a chance to add some thoughts I have been having.
First off, the battles look amazing and I love that tactics, terrain and abilities play a strong role here. As the scenarios show, there is room to turn the tide, if you play your cards wisely.
That said, I would tentatively share the concern voiced by others that these battles could slow down the overall game flow a lot (too much?). The beauty of EL's battles was that they were generally quite quick, because you only had 6 times to think about and issue commands. Here this can happen more often as you see the result of each unit's action. Longer battles can work, but I don't think I'd want a larger one more often then every few turns, if even. Judging by EL's game flow, it might be a bit too frequent for my taste.
You may want to think about smart automation for battles. I liked AoW

's combat retry function, as it safely eliminates the need to fight trivial battles. Is it in-built save scumming? Yes, partly. But do I really want to spend my time as emperor leading small scale 2:1, 3:1 superiority battles when there isn't an obvious terrain risk? Nah, for me at least. Others probably want to fight out everything and love the additional detail.
On more technical aspects, I must admit it took me a while to understand the information about minimum and maximum damage dealt in the attack preview field, both the symbols and the health bar. Maybe add the damage symbol before the minimum damage or after both the minimum and the maximum damage. For the health bar, maybe use a stripped red/green bar instead to display the drop in damage? Or something lightly flashing? (a different colour scheme might help with colour impairments, though the red/green symbology is pretty heavily embedded in games these days). Also, maybe a little number above or beside the health bar to indicate current/max health?
Should there be an option to have any commands be confirmed? Even in the dev live stream, the dev accidentally executed the wrong command, because of a small mouse movement. Seems especially relevant if you want to explore the potential results of more complex commands (first move here, then attack this unit from that spot).
Will there be a live combat log? Might be nice to track what your opponent has done if you missed which unit exactly was moved and how so much damage was dealt. More a QoL feature that can come later.
Not sure it was covered or shown in a stream, but what's the consequence of retreat/winning by capturing the flag? In EL, retreat mean all retreating units lost x% of maximum hit points (around 50% I think). If this happened when the flag is captured, then the mechanism seems self-defeating. It's designed to keep an enemy from avoiding engagement. And yet by capturing it you allow that defending partly exactly what it would have wanted by kiting - escape that immediate battle, albeit at reduced health. But I guess it doesn't work quite like that ...
That being said, what options do you have when facing impossible odds? It would strike that in many historical engagements, an army would only fight a losing battle if it has to i.e. no safe route to escape and/or no reinforcements nearby. And the premise of a "fight to the last man" battle in many strategy games seems quite at odds with many actual battles. Are there are options to retreat, to stall for reinforcements? Certainly battles being bound by rounds helps. Of course, it needs to be balanced for playability. Chasing up fleeing armies forever is no fun for anyone ...