RTF is a global modification that replaces all towns in the game.

If such an idea can be implemented, then orcs would fit the lore best, as Sareth enhances them with magic, and here it would be similar to Warcraft, when Gul'dan empowered Blackhand (this is how it was in the movie; I haven't played the game). Here, the Orcs pay a high price to their ancestors so that they can grant strength to their warriors (in my opinion, this fits very well into the lore, as the orcs from Dark Messiah revered their ancestors).