Complex sentence: The Chinese field command had to change their tactics, using small-unit attacks around Vietnamese positions instead of frontal attacks by human waves, which resulted in the fall of Thâm Mô to the hands of the PLA 163rd Division.
Split into simpler sentences: The Chinese field command had to switch their tactics, using small-unit attacks around Vietnamese positions instead of frontal attacks by human waves. The change resulted in the fall of Thâm Mô to the hands of the PLA 163rd Division.