I’m starting to wonder whether the reason St. Thomas never wrote a separate question on analogy is because he saw it as much more simple and unobjectionable than we do, and that our confusions are based on a convoluted and over-dramatic notion of what analogy is. Why not say that analogy is a second imposition, and that’s it? As second, it is known only in relation to a first. So taken, when we say “being is said analogously of God and creatures” what we mean is “The meaning of the word ‘being’, when it includes God, can only be a secondary imposition of the word, and the first imposition of the word is not said of him” or “when we consider what the word being first means, it cannot include God, though a second meaning can”. St. Thomas gives various reasons why this is so (God is a cause while we first know effects, etc, see ScG I 32-34) We might even, for all I know, have a meaning of the word being that can be said of God and creatures- but all St. Thomas insists on is that the first meaning can’t include God.
Why this order in impositions or meanings? Because there is an order in our knowing. That is all. Contemporary English speakers figure that a word can mean whatever we want it to, whenever we want it to, and so we find it odd when St. Thomas insists there must be an order in meanings. In fact, our tone-deafness about order in meaning is probably founded on our general tone-deafness about any order of knowing- or maybe even of hierarchies altogether.