As far as I know, the Khazars had quite a lot of trade built up between them and the Kievan Rus', their armies would probably be similar-looking and their tactics probably not that diverse from one another. Considering that the Khazars lived just down the river from the Rus', the trade between the people's would have been a very significant factor in their income. If you pick up a history textbook on the Rus' you will be certain to find the Khazars in there.