15thc perception on swallowtail merlons?

[Linda]

Given that the two (the castle and the wall) are placed in altogether different portions of the chart, I think these are just merlons casual to the artist - the merlons that he's been accustomed to. So when he has to depict merlons, his first and natural choice is swallowtail.

It depends on where the maker(s) had been, had seen (in drawings), or were located, as to whether the examples that inspired the drawings were old, new, or otherwise, since they existed long before in some places, added at the time in others, and continued to be added for centuries thereafter in many different places.  

It can still add meaning, if they thought of them as political, but there is no real way to know if that was the case.