Sequential word repetitions in the VMS

[david]

Is that too many as compared with natural languages?

I have no idea. But those four words you quoted are some of the most famous Voynich words out there.
I also don't know how this compares to other handcopied manuscripts of the era. It could be a way into resolving the "original or a copy?" question.

Is not the repetition issue too exaggerated?

I think the issue is not direct repetition, but rather many similar words repeated, as in Timms pairs and [ah-hem] Jackson sequences, which are not features of written languages.