China was correct ideologically in rejecting the denunciation of Stalin for one thing, and it's part of the reason the PRC still exists and USSR doesn't. Also, their foreign policy was at times shitty during the split but not nearly to the extent of the black and white picture you claim. They supported a lot of AES and anti-colonial movments in Africa and elsewhere while Mao was still alive, sometimes spending much more than the USSR in doing so, since they were competing with the USSR for prestige and the role of leader of global communism. You can read about a lot of the details of that in Maoism: A Global History by Julia Lovell.