No that's a good one what is it?
It is quite cleverly disguised, and compounded.
When trying to break down an argument, first find what's called the logical operator. Words like: therefore, because, ergo, or in this case, "so". Everything before the operator is the premise, and everything after is the conclusion.
"God, or a primordial being is perfect in every way so even if something seems out of the ordinary or mindless to us, I still think it's all part of a certain plan, even if it takes a few years or even centruries for us to realize."
The premise is "God, or a primordial being is perfect in every way." And it's implied that this is in reference to his plan.
The conclusion is "even if something seems out of the ordinary or mindless to us, I still think it's all part of a certain plan."
So what's being said is that God's plan is perfect in every way, because God's plan is perfect in every way. It's a tautology, also known as begging the question. The conclusion is just a restatement of the premise.
When we add "even if it takes a few years or even centuries for us to realize" it also qualifies as a specific form of special pleading called immunized hypothesis. If we find evidence that appears to disprove that God's plan is perfect, it doesn't count, because we just aren't capable of seeing the perfection. This means nothing we can ever see will falsify the idea; we can only confirm it.
And again, I'll point out that Gregor says the idea is arbitrary. I'm not trying to make an example of anyone.