Dune II cannot be called a Warcraft-style game, and maybe the other way around - Dune II was a precursor to Warcraft, simply since Warcraft came out a year after. Dune II was a sequel to Westwood's Dune, which was an adventure game and nothing like the sequel.
The story is based on the book "Dune". As the game starts, you can pick one of three houses - the noble House of Atreides, the secretive House of Ordos and the evil House of Harkonnen.
The basic structures were the same for all houses (IIRC), but the graphics and the readers' voice were different to suit the houses' stereotypes. For example, the Atreides voice effects were performed by a pleasant female voice, the Ordos - by a pleasant male voice, and the Harkonnen - by an aggresive male voice.