The "model book" hypothesis is interesting. An idea ahead of its time?
But I can imagine another pedagogical scenario that might fit the form of the work even more closely -- namely, that the Voynich Manuscript was contrived as a fiendish form of
punishment.
Something like the assignment of writing "I will not bring frogs into the classroom" a hundred times. But worse!
Teacher: "Here's the Nonsense Script and a set of complex but pointless rules you'll need to follow when using it. Now write a hundred lines of this stuff, and show me when you're finished so that I can check your work for statistical consistency. Oh, and they're not quite the
same rules as last time: this time you'll need to... hmm, let's see... start using this new
[ed] combination a lot, just to keep you from getting comfortable. And no more taking time out to draw pictures of weird plants! This isn't supposed to be enjoyable, you know. Going forward, any line with a plant part taking up space in it will
not count towards your total. Got it? As before, the cost of the vellum will be added to your tuition fee, so that your money pouch will weep along with your cramped fingers and fatigued mind."
Student: "Yes, sir. I'll get to it right away, sir. Sorry about that incident with the frogs, sir. Won't happen again, sir. [
Aside, to self:] Oh, so you didn't like the plants, huh? Well, you lousy old grouse, let's see what you think of some
nymphs...."