Look brother, the reason why our kingdoms did not keep records was because we did not have that centralised and well managed bureaucracy which itself is indication of poorer administrative set up. Our system was based on traditional caste and feudal loyalties. So while in China, we had officials recruited by exams( very tough ones) , Indians did it by appointing people of same caste or creed or some from a family with some martial background.
China remained most advanced civilizaton till 1400AD. Just see this painting from Bengal of 11th century
Now see this from Song age from same timeperiod. What a fine piece
A picture is worth thousand words as Chinese say so brilliantly.