What's the difference between God, electrons, and Santa Claus?

This question appeared on my Philosophy of Science midterm exam and this was my response. I will try my best not to edit my initial answer, as to stay as transparent as possible.

Right below is the exact question as posted on the exam.
"Critically evaluate the relationship of the following sentences from the standpoint of the debate between the scientific realist and the anti-realist. Whose view is right, and why?
a. God exists.
b. Electrons exist.
c. Santa Claus does not exist."

All three of these items are theoretical entities, as we know, however only one is well-confirmed enough to be recognized by both scientific realists and non-realists.
a. God exists.

Some realists would argue that the existence of God is indisputable and a fact. Their primary defense for this claim is that everything is God's creation. When analyzing theoretical entities and their affects on the world, the immediate answer to what God has created is, well — everything, even you! To the antirealist and non-realist this is unequivocally false. For example, to the empiricist or any other non-realist could argue that God's existence is not only not provable, but a mere creation of man's mind. Of course, the realist would only say that it's not until after death that that we "see" God and his "true" power, in most cases. To antirealists, this is simply not justifiable, and they have a point. The idea of God and only way to "see" him is far too convenient, in that realists could never prove his or her or its actual existence or presence.

b. Electrons exist.
Electrons on the other hand are far more provable and justifiable than the existence of God. The existence of electrons can be agreed upon both realists and non-realists to an extent. Fine's article on the NOA (Natural Ontological Attitude) says that antirealists could possibly agree on the existence of electrons, to an extent, but that realists would only emphasize, "There really are electrons, really!" Realists and non-realists might not share the same essential rules of existence or values but "a core acceptance that both parties share." Fine introduces the NOA to not be a definitive stance with scientific realism or antirealism but a whole other stance entirely. This is what Fine had to say in regards about NOA and theoretical entities, such as electrons: "...it is possible to accept the evidence of one's senses and accept, in the same way, the confirmed results of science." Ultimately, I am using Fine and his theory of the Natural Ontological Attitude to bring realists and antirealists together in that electrons are well-confirmed enough to be considered nearly true. (Here my professor adds "Nice effort" 😬)


c. Santa Claus does not exist.
Simple. The blatant absurdity of Santa Claus' existence is laughable in that we know, for a fact, that he is more of a nursery story or rhyme. The only difference between him and God is that so many people believe in "God's existence" that is would be a miracle if he didn't exist. In the end, scientific realists and antirealists would agree that Santa Claus probably is not real.
In the end, all three are connected in the sense that they are theoretical entities, but on completely different levels of existence. In that, electrons are well-confirmed enough to be considered by both realists and non-realists. God can somewhat be defensible by the realist and Santa Claus — a joke.

Side-note: Looking back at it, I seem to generalize groups but I wrote understanding not all realists have the same way of thought, just as antirealists do not all have the same exact thoughts. I also used non-realist and antirealist interchangeably, so sorry if that causes confusion. I received a 24/25 for my response.