I found that having 2 dragons is an I Win button. They aren't easy to get, but putting two of them in an army makes that army unbeatable. Even one will make it nearly unbeatable, but epic level monsters can give you trouble with just one dragon.
Other than that, there are a bunch of unit tactics you can use that are effective. I like having archers with the impulsive trait, that allows them to go first. That allows you to damage anyone on the tactical map before the fight even begins. Again, this trait isn't available until a fortress town reaches level 3, which takes a while.
Other than that, there are a bunch of unit tactics you can use that are effective. I like having archers with the impulsive trait, that allows them to go first. That allows you to damage anyone on the tactical map before the fight even begins. Again, this trait isn't available until a fortress town reaches level 3, which takes a while.