St. Thomas Aquinas maintained that every angel is a different species from every other. If so, and I’m inclined to believe it’s so, then each guardian angel is different from every other one; greatly different. If they are differentiated, then in what way are they differentiated? We understand their natures are geared to specific functions. They are not interchangeable.
We, on this earth, have no idea how many angels there are of any kind. So how many guardian angels, then? If each is tasked specifically for a particular person, then perhaps any given guardian angel is uniquely created and suited for one person only. The angel can read my mind. It knows how my DNA works and how my brain chemistry works. It knows my thoughts, but not only that, it knows my patterns of thought. It knows how my particular personality will likely react to certain things. It knows what will tempt me and what won’t. It knows what will uplift me and what won’t.
It knows me far, far better than I know myself. And when I die, then what? Does it go into “angel storage”? Does it get a transfer to somebody like me? Or does it stay as my companion for all eternity; the difference being that I can then “see” it with the “eyes of eternity” and communicate with it? Will it somehow facilitate my “perfection” as a child of God? Will it perhaps accompany me into purgatory if that’s where I go? Will it help me there? Train me and help me purge myself of all that’s sinful and self-centered?
After all, if God creates billions of humans, is there some reason why He could not or would not create billions of angels as well, each specifically created to be the guardian of one person only?
We don’t know. But I’m inclined to at least believe there are billions upon billions of them and that each one is wise beyond all imagining, but most particularly wise as to one human being.