Here is the argument's basic form:
P1:
(UA) Belief in God is (nearly) universal.
P2:
For any given proposition P, if belief in P is (nearly) universal, P must be true (i.e,, P must obtain).
P3:
So, if belief in God is (nearly) universal, God must exist.
∴ God must exist.
The traditional formulation is perhaps the most well-known version of the common consent argument. Versions of the traditional formulation appear in Cicero's On the Nature of the Gods (book 1, section 17) and Plato's Laws (book X, 886).
I think we need to be careful about assuming that Plato's argument in Laws X is actually in this family of argument; the point being addressed in context is whether it is easy to show that gods exists, and Clinias says that it is, for two reasons: (1) the order of the world makes it obvious to the senses; and (2) Greeks and barbarians alike already accept the existence of gods. It's possible to read this as two arguments for the existence of gods; it's also possible to read it as an argument for the existence of gods and an argument that you hardly even need that; and it's also possible to read it as an argument that it's easy to show, or perhaps that it's the sort of thing that one need not worry about accepting. The Athenian agrees, but goes on to say that there are people whose corruption of mind Clinias has hardly begun to grasp. Thus one could well interpret it as just saying that since lots of people regardless of society agree that gods exist, there's not much need in the context of law to worry about defending it -- if we take that interpretation, the Athenian rejects it in the dialogue on the grounds that it underestimates how perverse atheists are, but it is in any case not in the particular family of argument identified by Rollins.
Cicero, who is presenting what he regards as Epicurus's argument, does put forward something roughly like this, but it's not the mere fact of universality that is doing the work in the Epicurean argument: it's that it is such as to suggest that the belief is not purely dependent on education and custom, and thus that it is implanted or innate in us. Then this, the claim about its entanglement with human reason, is what yields the conclusion. Cicero later in the work (book II, section 2) has his Stoic philosopher note the resilience of the belief as a confirmation: time destroys error and fiction, but belief in the gods is quite stable and resistant to change among populations. The argument too seems to be a somewhat different argument from what Rollins has in mind; for instance, this form of argument does not fall victim to the criticisms that Rollins goes on to give of the traditional argument. For instance, Rollins says, " traditionalists fallaciously presuppose that (near) consensus on any given proposition P provides proof that P is true". This is certainly false of the argument as we find it in Cicero.
It's worth noting that neither the argument as we find it in Plato (regardless of the interpretation we take) or as we find it in Cicero has any problem with the first difficulty Rollins notes: "it's highly unlikely that belief in God (or gods) was ever universal, or even nearly so". The Ciceronian version does not depend on universality, but on naturalness. And the Platonic version is presented explicitly in a context in which everyone recognizes that there are atheists -- it's just not relevant to the point at hand, which is whether atheism is a serious enough issue to address directly. And we also have to keep in mind that ancient and medieval philosophers tend not to be very strict about universality in general -- they don't treat occasional exceptions as counterexamples to universal statements as long as the exceptions can be explained by some kind of impeding or defective cause. (Their universals tend to be 'Aristotelian universals', as we call them now.) That nature occasionally produces freaks of nature, the odd lusus naturae, some preternatural phenomenon or out-of-the-ordinary monster, was an extremely common view.
I think, if we are going to talk about 'traditional formulations' of consensus gentium arguments, we should take the Ciceronian argument seriously and hold that they involve an intermediate step to what is natural or fitting to a rational creature.
