Why I think that the copyist(s)/scribe(s) did not fully understand the material

[ReneZ]

There is nothing unusual about the MS having mistakes. It was made by humans. 

There are still very many unknowns (variables if you will) in how the MS was created. It's not just a choice between two options. When judging certain aspects, it is quite natural to be guided by one's own expectations about some of these variables, and I would not blame anyone for doing that.

Meaningful or not?
Scribe different from author?
Scribe understanding the source or not?
Was the 'translation' (if there was one) already done by the author, or did he just provide the rules?

This is far from being all, and some options are already conditional on other options. 

What's more, some other aspects may not have been constant for the entire MS. In particular this applies to the quality of the draft  (if there was one). Even more in particular, in the zodiac one may wonder how much of the drawings were improvisation by a scribe. In the beginning, the figures are reasonably well spaced but this deteriorates as it goes on.

I saw a suggestion that labels were all added at the end. I don't know how we could conclude this, and I also don't see how this affects the point I brought up in the opening post.

So to come back to that. I specifically selected that case (the only one I find sufficiently telling), because it holds, regardless whether the text is meaningful or not.
The label is written in the wrong place (probably!), even while it could have easily been written in the correct place. Also when the MS is a hoax.

In my opinion, the original author would not have made this mistake.
Yes, this is subjective.

The only reason why I want to point this out is, because it can have major consequences on the accuracy of the text. We may be looking at something that has been distorted very significantly due to ignorance (with apologies to Ulrich et al).