You also have to consider that the USSR and China being linked heavily could have driven China down with the Soviet Union, because of the split, China was able to withstand the collapse, come out stronger on the other side and move into a position much greater than that of the Soviets. Without knowing exactly the internal thoughts of the leadership of the CPC it is difficult to know what they were thinking, but perhaps they saw the the dramatic shifts coming from the govt after Stalin’s death, and they were not feeling confident that the Soviet Union was indeed a reliable ally. If they were willing to turn on Stalin shortly after ww2 and his death, who was to say they wouldn’t do the same of Mao. Fickle allies are bad news, especially fresh after a Civil War and in the throws of cultural revolution. I think both sides took the split a bit too far though,they could have kept temps low and gone their own ways, but they got very aggressive with each other which sucked a lot.