What he listed were the BG2 Keeps/Strongholds and thus the BG2 classes. Without getting into the more complicated stuff, Thief is the AD&D2 version of Rogue, or rather is the class that eventually became Rogue.
Those were the keeps each class would get, Funnily, in BG2EE Shamans don't get a keep as far as I know, which really frustrated me a bit.
