All in all, there weren't any huge obstacles in the way of the international release of Diablo, and even went slightly better than Warcraft.
Thunderbolt Entertainment gained some fame overseas after selling Warcraft afterall, making an especially deep impression on players who liked themes like this, which was why Diablo managed to garner so much attention before it started selling.
Moreover, Western Fantasy themes, especially in Europe and America had always been popular, moreover, Diablo was an RPG, meaning that it'd have a bigger audience than an RTS game like Warcraft.
One thing that was different was that the international players didn't have too many doubts of complaints when it came to a third person RPG as there were more indie games overseas, with more players liking single player games.