So, with the new Ungrim news, the new Giant Slayers, Karak Kadrin focus, etc, this would be a grand chance to give Dwarf Factions (or maybe even just Ungrim's faction) a new melee hero better suited for assassinations / damage output in battle.
They'd be weaker defense-wise from Thanes, but deal more damage (and bonus vs Large) then them, with the best assassination chance out of the Dwarf Heroes (since, come on, we all have gotten annoyed at least once on the Grudges and Quests that require a successful assassination). Maybe even create 2 variations for two weapons vs one weapon, higher weapon strength vs armor piercing?
This is fairly reasonable in my opinion due to how varied the newer factions heroes have been!
EDIT: The Dragon Slayer would have a two-handed axe for armor-piercing, the Daemon Slayer would have two one-handed axe for damage output. Maybe give them a passive specifically against Dragons or Daemons, but in general they'd be the same hero but with slightly different combat strengths like normal Slayers vs the new Giant Slayers.