Is Conflux a broken castle?

For the past month, I've been playing as a hero from the Fortress faction with a specialization in magic resistance. Against elementals, it's a guaranteed win. They waste their first spell. It's quite fun! It seems like dwarves have some kind of immunity. And so on.

On the other hand, you just need to know how to play as the Castle faction (there are no inherently good or bad factions). I just don't know how to play as the Tower and Necropolis (I simply don't like them) and the Conflux. But my friend crushes me when playing as the Tower, and another friend knows how to win with Necropolis using the Conflux.

To each their own, IMHO.