The 'Chinese' Theory: For and Against

[Jorge_Stolfi]

But if the VMS Author got his Zodiac scheme from Alfonso, why did he think it was OK to split Aries and Taurus into two 15-thing parts?  

The reason why they could be split without issue is likely the same reason why the author of astrolabium planum felt that he could split it into 30 individual squares. T... perhaps he wished to use the given space more cleanly, or thought it looked nice, or perhaps he drew the circles too small and decided to split them in 2.

So there is still no Western precedent for splitting the zodiac into chunks of 15 "things" rather than 30 "things" (or 12 "things" as in the Astrolabium).

On the other hand, the Chinese "Solar Terms" scheme splits the Zodiac into 24 equal parts. Which would be 15 degrees of arc each.

Agreed, that coincidence (24 parts instead of 12)  is rather weak evidence.  But it is not zero...

All the best, --stolfi