The plow is not a single invention.
A scratch plow is very different indeed in its use and effects from a moldboard plow.
Improvements in plows and harnessing methods during and after the Middle Ages took plowing from a process requiring six oxen to one requiring a single horse.
With respect to the plow, the description talks about prehistoric use and says "improvements in the plow's design made farming so efficient that people could harvest far more food than they needed to survive.
I agree with you, and assume the authors of the list agree with you about the plow not being a single invention.