Then you maintain your G-d is the nothingness, which is a reasonable cosmology. As it's all symbolic of ineffable concepts, it doesn't make any difference what name you refer to the nothingness by. However, the second you say "This is the nothing", then you've started categorizing. Simply by working within a trinitarian framework you have categorized deity - G-d is this, that, and the other, separate but complete within themselves. If Father, Son, and Holy Spirit can each be distinct, yet G-d, then denying that G-d can also be Thor, Freyja, Zeus, AShRH, Inanna, Medb, etc. is saying - in essence - that there are things which G-d cannot do. I don't place limits on Her, personally. G-d Herself is capable of whatever She so chooses. Personally, I hold to a primary Quadrinity of archetypal deties, and find most fit within those stylings. Father-Mother-Son-Daughter generally fleshes out the cosmos.
Also, I've been face-deep in spiked eggnog today, so my metaphysics are loose.
I guess if you define Thor, Freyja, Zeus, etc. the way we define the Father, Son, and Holy Spirit, then we're not discussing Hellenic polytheism anymore but Hellenic Polytarian Monotheism. And in that case, I'm cool, I'm only arguing against polytheism.
After all, we believe the 3 persons are consubstantial with the 1 divine nature that is the only G-d, so if the parallel exists, then there are multiple persons (Thor, Freyja, Zeus, etc.) within the 1 divine nature that is the only G-d, and then its no longer polytheism, but Hellenic Polytarian Monotheism.
But if you are supporting Hellenic polytheism, then the parallel is invalid, and my argument continues:
"Wouldn't the true G-d be the Being that contains the certain "pieces" each of the g-ds have?"
And thus, my 1 G-d can be the one who contains everything, but the multiple g-ds cannot contain everything, they being contained by their surroundings.
But I don't know, why is it wrong to say "This is the nothing" (although I deny my G-d is "nothing", I don't believe there is a "nothing" from whence the One came from, as you said)?
And I don' think I've denied that G-d can also be Thor, Freyja, Zeus, etc. I've only said there cannot be polytheism due to the greatest is always superior to the parts in which it contains. And this is so because of logic (which we can go over its self-evidence). So surely, G-d can destroy logic, He being omnipotent, but the fact that He didn't shows He supports it for a point, to lead us to truth, which leads us to my main argument again:
"Wouldn't the true G-d be the Being that contains the certain "pieces" each of the g-ds have?"
And I'd like to hear about your Quadrinity of archetypal deities thing, it intrigues me.