Welcome, @Annmaree_Jackson,
Others might disagree, but I feel an effort of this scope and complexity requires an interactive discussion in order to give meaningful feedback and avoid potentially giving incorrect feedback.
It seems like you’ve already determined the need for 120 or so projects (and maybe another higher-level one if I understood correctly), and now that’s creating complexity in and of itself.
One of the early questions I try to suss out with clients is where to “anchor” work in Asana–using which Asana work object. A project may be the right call, but we can’t determine that with a Forum post.
I gave a workshop on this one question (with a bunch of related info), and you can check out the video if you think it might help:
Thanks,
Larry