I get the feeling that Divide and Rule is given far more credit than it deserves. Its not like any foreign ruler could come into India, play one kingdom against another and conquer the country.
The British managed to do that, not because of their policy but because of their technological superiority. After all, even a divide Indian empire could field an army many times the size of most European force. And if you look at the major battles between Indian and British forces (with the exception of Plassey), you'll see that the natives lost not because they were fighting amongst each other, but because they were unable to match the firepower of the Brits in the battlefield.
Neither the Chinese nor the Turks had that level of technological superiority over the native Indian Kingdoms.
Is that actually true? I haven't looked all that deeply into it, but I was always under the impression that the Europeans advantages over the Indian forces were based on tactical superiority and political maneuverings, rather than technological superiority.
And it really depends on the time period. The 19th century British had a decided technical advantage over Indians, Chinese and Turks alike. The 17th century British? Not as much. It wouldn't take much for the Turks or Chinese to achieve a level of technological superiority over Indian kingdoms.