I think the thing is that the relevant archives for the sino soviet border clashes and tensions of 69 were opened but only for a limited amount of time and only very few historians, domestic mostly , had a access to them so there is probably some more accurate historiography in either language based on archives but not really easily available in english

Here is a recently declassified emergency report Kissinger got on the issue in 69 https://nsarchive2.gwu.edu/NSAEBB/NSAEBB49/sino.sov.9.pdf