From the Christian perspective, God is
perfect, or, if you prefer, a ‘maximally perfect being’ as I’ve heard it expressed. Knowledge is a capacity; as God is perfect, he must needs possess perfect knowledge.
That’s the short answer, and there really isn’t a long one I’m aware of
As to the homunculi, yes, you would be God to them; you created them out of not-quite-nothing. You’re not omniscient, as far as you’re concerned – but to them, it’s a different matter. You, as their creator, know everything they are capable of doing, have ordained the rules of their universe, and can predict the behavior of the system down to the tiniest level you care to.
As far as they can tell, you’re all-knowing.
I don’t think this is so
1. In the Silmarillion, we have
- a story
written by Tolkien, a human being, who “sub-creates”:
- Eru Iluvatar - who functions as God by creating
- the Valar & Maiar: collectively known as the Ainur
who are superior beings compared to:
- Elves
- Dwarves
- Men
- Ents
- (and of course Hobbits, who aren’t mentioned)
Question: does this make Tolkien a God-figure compared to (say) the Valar ?
I don’t
think it does. Within the story, the Valar are (roughly speaking) demiurgic figures; they can’t
create ex nihilo, but they can
make, much as an artist might. (One of the signs that the fallen Vala Melkor is deteriorating, is his gradual loss of freedom to change his visible form, which goes along with his gradual loss of
moral & *creative *freedom: he has more *power *than all the other Valar, but less
scope to use it in varied ways.)
IMHO, Tolkien functions as a demiurge, nothing more. ISTM that God - the Triune God of Christians - is (AFAICS) the true Creator of Tolkien’s invented world, as well as of its sub-creator. If this is correct, then God is as present to an Elf or a Vala or a Hobbit - that is, to a being in that world - as to a human being in the “Primary World” which is AKA “the real world”. If God were not present in feigned or Secondary worlds, they could not exist, any more than this one could. (Where this leaves the figure of Eru, is not clear…) God is the Reality - we are all His fictions: Elves & authors alike.
**2. **Tolkien ISTM was not all-knowing in relation to his Secondary World, & could not be, because he was as truly a creature as his “sub-creations”. God, OTOH is neither created nor sub-created; to be God, is to be free of all derivation, in all worlds, whether sub-created by men, or of any other kind. God is therefore infinite - & that means that God knows infinitely; that nothing in any world, actual, possible, hypothetical, no matter its time or dimension, can in any manner be hidden from Him.
To be all-knowing is not something that God “could have” not been - God’s Knowing is identical with His essence; it’s not “in potency”, but is eternally actualised: what He does, is Who He Is. He is His Knowing - if His knowledge were not infinite, he would not be God, but only an angel. So it would be necessary to find the real God; & that is He.

All His attributes are identical with Him.
We see His Knowing & His Essence as separate, & even as separable, not because they are, but because our intellects know things by forming separate concepts about those things. This comes of our being a union of matter & spirit; & is made bad by our being deformed by sin. And because we are not identical with God, our intellects treat God as though He were just another object of knowledge, another “something out there” to know, even though He is nothing like any creature.
Hope that helps.