The nymphs are possibly inspired from Dante manuscripts

[Rafal]

But go over to germany, and a huge amount of manuscripts contained a compilation of various works and texts, basically depending on which works the person wanted.

Yes, the formal name for it, I believe, is a composite manuscript.
And VM is probably a composite manuscript too.

But I think what we are discussing here that even in single section we have imagery coming from different sources, all mixed up.

For example Quire 13 (bathing nymphs) seems to take inspiration from:

- Taccola (shape of some streams and ponds, pipes)
- De Balneis or Dante (naked bathing nymphs)
- some religious sources (some scenes resemble giving alms to the poor or Jonah eaten by a fish)

and possibly more.

Mixing imagery from engineering book, bathing book and religious book in one place is certainly uncommon.