What is the difference between the “Tribes of the East” and the “Hammers of Fate” expansions?

Heroes of Might & Magic V: Tribes of the East
Don't buy this version; it's 100% pirated. I made the same mistake.
I saw it, my eyes lit up, and I bought it right away. I was stingy and bought it; I should have waited!
So, go for the second option.