15thc perception on swallowtail merlons?

[DG97EEB]

I'm don't sure it matters, does it? The origin of the swallowtails is well established. The fact they persisted on castles for centuries after is not contested. The point is if we assume that although perhaps not literal, the imagery is at least deliberate, one can reasonably infer a place of not exactly a time. The time we already have from RC dating, so all that can reasonably be inferred at this point is some point in the 15th century, someone who had some connection to these environs decided to copy this on to vellum/parchment.  My point is whether if we take a combination of factors on that page outside the swallowtails, we might learn anything further?