I agree 100% that any use of packages can be intimidating for newbies. I experimented at first with creating the models without using numpy and I thought that it actually made it less clear rather than more clear. It's obviously a tradeoff--you see where everything comes from (rather than np.mysterious_function()) but you take 5 lines of code to do the same thing that a single numpy command could accomplish. I felt in the end that it distracted from the real purpose of the code, which is to demonstrate how the model works.
Do you think a compromise would be to add a section to the appendix introducing numpy? Introducing arrays, random instantiation, stuff like that? Otherwise I might consider adding a no-numpy version in the future.
Thanks so much for your feedback!