What we see on a closer examination of the pagan gods is that the names they give them are inconsistent with either reality or each other. Jupiter is really Saturn in disguise, and is also referred to as "Money." ("Pecunia.") Mercury and Mars seem to be just named after human events and happenstances of grammar, while the stars are seemingly randomly assigned to gods.
To repeat, I think Augustine's analysis of the pagan gods is getting tedious. But then again if I lived in his culture I might think it critical. Just as if a modern writer were to go on about atheism or naturalism or some other dominant worldview today I might find it to be of the utmost importance.