Why is the MS not a copy of older, non European sources?

[Sam G]

What nobody ever seems to consider is the possibility that the illustrations are more recent than the text.  ...

I've considered it many times but the evidence (text accommodating the imagery rather than the imagery accommodating the text) appears to lean toward the drawings being there first. There are examples pointing in this direction on almost every page.

But I'm not talking about whether the text or illustrations in the VMS were physically written first on the parchment, I'm talking about which originated first as far as the history of the content is concerned.  So what I'm proposing is that at first you had text only (as well as possibly some illustrations significantly different from what we have now), then someone copied this text and added illustrations to it.