Seleucid, Demotic and Mediterranean mathematics versus Chapters VIII and IX of the Nine Chapters: accidental or significant similarities?

Similarities of geometrical diagrams and arithmetical structures of problems have
often been taken as evidence of transmission of mathematical knowledge or
techniques between China and “the West”. Confronting on one hand some
problems from Chapter VIII of the Nine Chapters with comparable problems
known from Ancient Greek sources, on the other a Seleucid collection of problems
about rectangles with a subset of the triangle problems from Chapter IX, it is
concluded,
(1) that transmission of some arithmetical riddles without method – not “from
Greece” but from a transnational community of traders – is almost certain,
and that these inspired the Chinese creation of the fangcheng method, for
which Chapter VIII is a coherent presentation;
(2) that transmission of the geometrical problems is to the contrary unlikely,
with one possible exception, and that the coherent presentation in Chapter
IX is based on local geometrical practice.