Turalyon as the “Fuhrer of Light” and the Alliance flag is not blue, but gold with a black lion. His enemy in that timeline is Zug Zug, the greatest Warchief that ever lived and first “King of the Horde”. This takes place right after WCII without Nerzhul tearing Draenor apart and without the Scourge happening. A young Varian at the time went from a king to a commoner as Turalyon conquered Stormwind and made it his. Making a living in Lordaeron, only to be acknoledged by Arthas or King Terenas, earning the rank of baron.
It’s so far from WC, that I think you should just make an original world/characters and write a short story or book.
Having fantasy hitler is a little on the nose, but I there is still an audience that likes having an obvious bad guy in their fiction. I would read it.