Nam primum in quolibet genere praeeminet alteri posteriori illius generis, et tamen non est causa illius. Primitas enim exemplaris non distinguitur a primitate efficientiae, quia primum exemplans alia in esse intelligibli, non est nisi primum efficiens per intellectum; et sicut naturale efficiens non distinguitur contra efficiens, immo continetur sub eo, sic nec exemplaris distinguitur ab efficiente. Sunt ergo duae causalitates contra se distinctae, scilicet causae efficientis et finalis.
Judging the soundness of the Latin text is well beyond my competence; that's Faber's domain. The present edition isn't a critical one (it includes no variants), but until the critical edition is available it's what we have to go on, though it has come under some pretty severe criticism from trustworthy critics. Taking the Latin as it is, though, I want to look for a second at the English translation. This passage gives a good example for why, granted all the good he's done for Scotist scholarship, the reader should be wary of relying on Wolter's translations for a precise grasp of Scotus' thought. Wolter's translation:
For the most eminent [species] in any genus excels each less eminent [species], and yet is not its cause. Note also that the primacy of exemplarity is not distinguished from that of efficiency, for the first to model another in thought is nothing other than a first efficient cause endowed with an intellect. Now just a natural efficient cause is not distinguished from efficient cause - indeed it is a subdivision thereof - so neither is the exemplar cause. Hence, there are only two sorts of causality that are distinct from each other, namely what pertains to an efficient cause and final cause respectively.
Here is my own translation:
Now the first in any genus is preeminent over another posterior member of that genus, and yet is not its cause. For the primacy of exemplarity is not distinguished from the primacy of effectivity, for the first thing exemplating another into intelligible being is nothing but the first thing effecting another through intellect; and as a natural effecting [cause] is not distinguished against an effecting [cause], but rather is contained under it, so neither is an exemplary cause distinguished from an efficient one. There are therefore two causalities distinct over against each other, namely that of an efficient cause and that of a final one.
Some of the differences in my translation are mere quibbles. I don't like Wolter's "efficiency", since the ordinary meaning of the English word seems just too far from its meaning here. More seriously, I don't see why he twice inserts the bracketed "species", which does not seem obviously demanded or implied by the sense of the passage. Some are not quibbles, however. While in places Wolter's translation is extremely literal, "for the first to model another in thought is nothing other than a first efficient cause endowed with an intellect" seems to me intolerably loose. It's almost as though he doesn't grasp the crucial point here, and so doesn't know how to render it precisely, and thus totally glosses over the relevance of this passage to the problem of intelligible being.
When I "model something in thought," there are two ways for me to do it, depending on what exactly I am modeling. Say I am modeling in my thought some mathematical object, the five platonic solids; or say I'm a detective modeling out scenarios to match the evidence of a crime scene. In these cases the objects of thought are already intelligible before I think of them, before I form my mind so that their intelligibility is activated in my intellection. The task is to bring what is already in itself potentially intelligible by the nature of its intrinsic formal integrity to being actually thought-out.
On the other hand, when I "model in thought" something like this blog post, or the plot of a detective novel, I am in a sense creating a new intelligibility, not discovering in thought what is already out there to bring into thoughtfulness. My act of intellection causes rather than is caused by the intelligibility of the intelligible object. However, my intelligible productions are artifacts. Like material artifacts, they don't have substantiality beyond that of the material from which they are produced. I can't create intelligibility any more than I can create physical things; I can only make new things by taking intelligible content and rearranging it in new ways. I can't invent a new platonic solid, although I can produce a new mathematical proof or pedagogical technique concerning the five that are always already there.
Now, the most pressing question about intelligible being concerns, not the way we think intelligibles, but the way God does. I can't make substances, only artifacts. But the substantial, natural world is in its entirety like an artifact of God's, who makes it. Is this true for the intelligible world as well? Does God think things, "model them in thought", in the first way or in the second? Does he think thinkables because they are first thinkable or are things thinkable because he first thinks them? If the former, one has to explain why finite things don't have some kind of eternal existence apart from God, in the separate platonic heaven of forms. If the latter, one has to explain how forms can have any internal necessity or non-arbitary features, and why in this case the potential seems logically posterior to the actual. By its looseness and imprecision Wolter's translation here totally obscures the fact that Scotus thinks that God produces intelligibles into intelligible being, a position which some later Scotists found untenable and ultimately incoherent. Someone reading only the English would not only be unable to tell which position Scotus takes, but even that this passage is relevant to the question at all. The question is not whether God is "endowed with intellect", but whether intelligibles are intelligible through the activity of his intellect or prior to his intellection.
A final note: in my opinion Wolter's "only" in the last sentence is neither justified in the Latin, nor correct. Scotus is not, I think, saying that efficient and final causality are the only kinds of causality; here he's talking about extrinsic causes, those which produce something into being, and not about the intrinsic causality of matter and form, which of course he recognizes. The point is that among extrinsic causes natural and exemplary causality are species of efficient causality, but that final causality is not; the point is not that there are no other kinds of causes.
So I reiterate a point I've made before: this sort of thing is not at all uncommon in Wolter's translations. Taken as a whole his work has been enormously beneficial for the study of Scotus in English; but it should never be relied on in place of the Latin for matters of detail.