As usual I think DeWitt is going in a very productive direction but I don't know that he explains it as persuasively as he could.
When he says ..... : "The necessity here appealed to is a necessity of thought, which becomes a necessity of existence. The existence of the imperfect in an infinite universe demands belief in the existence of the perfect. " .... I doubt it's best to use the words "perfect" and "imperfect" because of the connotations of magic those words carry.
In the very next sentence DeWitt quotes what I think is the better alternative: "Cicero employs very similar language: "It is his doctrine that there are gods, because there is bound to be some surpassing being than which nothing is better." 72 Like the statement of Lactantius, this recognizes a necessity of existence arising from a necessity of thought; the order of Nature cannot be imperfect throughout its whole extent; it is bound to culminate in something superior, that is, in gods."
So I wouldn't say we're talking about "perfect" vs "imperfect,' but rather more in the line of a spectrum from poor, good, better, best -- in that whenever you line up a spectrum, you're going to have *something* at the top of the spectrum. Simply being at the top of the spectrum does not mean that you are of a different type than what came before -- if you weren't of the same type you wouldn't be on the same spectrum in the first place. So simply being at the top of the "living beings experiencing pleasure" spectrum doesn't mean necessarily anything more than that all your time is pleasurable and that you don't ever have to die. Translating Cicero as saying "surpassing" does not require any kind of "magical" connotation.
That kind of interpretation would seem to me to be consistent with the way Lactantius and Cicero are understanding what Epicurus had said, and it would be consistent with Epicurean physics and not introduce any kind of "magical" analysis of deriving the existence of a 'supernatural' being from the existence of the "natural." That's an obvious non-starter under epicurean physics and should not even be entertained as a possibility of what he was saying.