Yes, George RR Martin is an avid student of medieval history, so there are details in GoT that are somewhat accurate when it comes to detailing life back then.
However, if Snoop is referring to Dragons and all that, then yeah...he's been hitting the hippy lettuce too much.
What you said sounds right, but the closest real-life parallel to “Game of Thrones” that I know of is a period called the Wars of the Diadochi (Successors), where Greek generals fought for nearly fifty years to grab as much of Alexander the Great’s empire as possible, after his death in 323 B.C. It has all the killing and sex, and even a bit of strange religion for those who are into magic. A few months back I listened to a hilarious history podcast about the period, from two guys who call themselves the Lesser Bonapartes. Originally they entitled it “Battletoads!”; now they have edited the recording and renamed it “Thank God Alexander’s Dead.”
George RR Martin is a plagiarist who simply stole ideas from Robert Jordan. The whole Game of Thrones is the Game of Houses in Jordan’s works. Only Jordan had less vile characters