I quite like the Stoic position of a unitary material with two aspects: πνεῦμα and matter. The enlivening Logos, the organizing principle of the universe is a beautiful idea. I do not as much like Plato’s five-part division of causes, as you’ve presented it. Certainly, it is true that without the various things which he labels causes, the existent things … wouldn’t. But, that doesn’t make them causes per se.
I may be re-inventing the wheel, here. But…
From a Stoic perspective, I would challenge the Platonic doctrine and make this change: There is one cause: ὁ λόγος. Full stop.
But the observations of Plato as to the nature of things which exist is worthy of note. I would propose to call those “constituents,” not causes. The existence of things which depend on constituent bodies would then be co-fated in a Chrysippean sense. Without the timely presence of the co-fated things, existing bodies, simply put, wouldn’t.
This incorporates a keen observation of nature of behalf of Plato, and incorporates it in a Stoic appropriate way.
I’m looking forward to the rest of your letter tomorrow.