Much more than that.

1). They have a dragon. There are already three dragons in the game (Necro, Dark, and Elf). The Dwarves have a fourth one.
2). Dwarves use cheat-like runes, which is where the imbalance comes from.
3). Dwarves are a race completely without any zest. There is nothing about them that really grabs you. For Mages, it's the floating castle; for Dark ones, it's the matriarchy and debauchery, with half-naked girls and whips; Necros have a whole cult going back to Heroes 3; Knights have valor and spirituality; Elves have a beautiful city and are beautiful themselves. As for Demons—just remembering Agrael is enough to be gripping. But Dwarves are just some race of old farts.
4). They are the only race where there are many humanoids across all levels from 1-6.
5). And they worship a dragon on top of that. Absolute nonsense. I read that Dwarves worship Thor, and his hammer is sacred to them.

Everything suggests that this race is unfinished and rushed, and therefore has no right to exist. Of course, I understand that the developers needed a race for the snow, but now Barbarians have taken that place. Dwarves must die!