In nomine Patri et Filii et Spiritu Sancte

Yikes, this is a hard topic to discuss.
But, I will be giving a lecture on the subject tomorrow, with respect to how the Mormon Church views it, so I better be able to say something.
The Mormon view of the Trinity is that the Trinitarian formula has specifically Hellenic formulaic components. I'm not sure how this is the case. With Platonic and Aristotelian Providential formulae, God is seen as a single source of wisdom, light, goodness and truth in the universe. But Hellenism generally has polytheistic roots (viz Zeus, Hercules, Hermes, Hera, Hades, Poseidon, etc).
But I have specific reasons for believing in a Trinitarian formula. I will explain this as I explained it to my sister. When we speak of perfection, we generally speak of it in terms of some specific quality. A perfect circle would only be perfect in terms of its roundness. But, there could be other perfect circles because if the circle is only perfect in terms of its roundness, then other cirlces, of different sizes can also be perfect.
However, if the circle is perfect in all aspects, then there can be no other perfect circle. Another perfect circle would be the exact same circle (mathematically speaking). If a perfect circle has a radius of 2 centimeters, then every perfect circle has a radius of 2 centimeters, but there every single perfectly round circle that has a radius of 2 centimeters is exactly the same in every way possible with regards to its circleness. Thus, it can only be the same circle. If there are no differences, there can be no way of distinguishing between them, then they cannot be different.
With regards to human beings, we can say that people are different because they also have some distinguishing characteristics that mark them as separate. There cannot be more than one perfect thing of any particular genus. Otherwise, the two would be indistinguishable from each other.
So, let's say there's something that is complete perfection. Not "a perfect thing x," but actual perfection itself. Thus everything about this particular thing would be perfect. There would be no flaws, no problems, nothing "wrong" about this thing. Then obviously, as I think I've explained there could never be anything else that could be perfect.
So we'd have to call this one perfect thing something. Let's call it God. This fits in with a Thomist metaphysical view of God. God is Goodness, Beauty, Oneness, and Truth. Furthermore, this fits the "omni"s: omnipotence, omniscience, omnipresence. So let's say there's one of these. How can there be a second perfect thing? There can't. So, if there's a God that fits these descriptions, there can be only one.
Then, if Jesus is God, if the Father is God and if the Holy Spirit is God, then there can be only one God. These three can be perfect, and perfection, but if and only if they are one.