“Heroes of Might and Magic V: Tribes of the East”

Why, actually, are the system requirements higher for the expansion? Graphically, it hasn't improved much; if the original ran on 64MB, the expansion should too.

P.S. The key word is "should."

Then why does it lag on my 128MB graphics card, even on the lowest settings? Moreover, this isn't just an expansion; it's a full-fledged game with all the files, not just an expansion installation!