I think attributing how Garlemald will be portrayed to just one character is the issue here.

We can absolutely have a complete dick of a foe in Zenos, and still get the feeling that there's much more the Garlemald than being an evil empire. In fact, having leaders like that portrayed as ruthless and other such unlikable characteristics arguably makes it easier for other elements of the enemy to garner sympathy or empathy without having to make those who are part of such a situation friends/allies.