No, this in-fact, is not true. Because The Great Holy Spirit, that being singular, is responsible for the creation of the Spirit of Light & Dark, which are plural:
From Light & Dark, their child is time:
From Light & Dark, fell the other Spirits, making the great eight spirits, responsible for the world itself:
Mind you, this does apply to other dualities, as world in this context means universe, and there are other fundamental forces within TenSura, such as fate and causality.
And we can explicitly prove this, as dualities that aren’t specifically mentioned are also included, like space-time:
So we can conclude that The Great Spirit created all dualities that shape and form the world, material and immaterial, as to which Veldanava & Rimuru transcended.
Hitchen’s Razor, therefore your argument is utterly worthless.