"The bounty hunter left after the battle was over. He said something about tracking down a smuggler on Tatooine. After the Kamino uprising, the Emperor decided an army of genetically identical soldiers was too susceptible to corruption. Future troopers would be cloned from a variety of templates. Though the 501st itself remained pure, the rest of the Imperial Army gradually became more and more diverse. We never really got used to the new guys."
January 1, 1970
https://en.wikiquote.org/wiki/Star_Wars%3A_Battlefront_II_(2005_video_game)