Finally had time to play this after building the computer; just finished Empire Chapter 1. I was surprised. I thought this was after Storm of Chaos due to it being a 2006 game, but apparently it's set in Magnus the Pious' time (220 years before Karl Franz).

Bright WIzard-san that you save in the first mission is your MVP. His fireball wrecks every fucking unit before engaging. As this anon >>2036894 already stated attach that flaming-ginger onto handgunners and they'll kill off Chaos Spawns and Giants in seconds.
Huntsmen are also useful as a scout unit (sucks that they can't get upgrades or hero attachments). Swordsmen can tank hard especially with Stephan spamming shield ability. Halberdiers are kinda, meh, they're squishy, too slow to flank, and feel better to just use cavalry.

The duel mechanic feels poorly implemented so far, as in the heat of battle you just forget to do it and I don't really see the advantage of using it over a normal battleline plus ranged support. The siege gameplay feels unfinished and ignorable (I just equipped all units to have kegs; gonna test whether the dialogue changes if I use ladders).

I also missed 2000's Jeremy Soule music, and this really reminded me of Guild Wars.