Linguistic differences and organizing plurals with the word "type"

I was proofreading a paper written in English by a native Spanish speaker, and came across the following phrase:

... that include this type of tools ...

And that really had me scratching my head for a couple reasons. First off, the writing of this particular author was generally quite good, and often what he wrote is exactly what he meant. Second, he had just described the evaluation tool to be one example of several that are used in the discipline, so it is obvious that he is writing about the particular tool of the study in the context of various others that exist.

This had me scratching my head for a bit, with me thinking about the phrase that definitely worked:

... that include this group of tools ...

After all, it's clear that the word "group" means a plurality of the things that constitute it. Yes, one can have a philosophical argument as to whether it is possible to be a "group of one" (even mathematics equivocates on this), if you need to make a philosophical argument about the case, then it implies that the case is so unobvious that - at best - it serves as an special-case exception to the general rule or pattern. So, given this recognition, a "group of tools" automatically means that there are at least two tools that define the group in question, and in that way, it operates as a collective noun in much the same way as "family" and "team" do.

But what about "type"? Is "type" a collective noun in the same way that "group" is? It didn't seem so to my ear, but that could just have been due to the conditioning of my upbringing. Indeed, the first definition given online is:

a number of things or persons sharing a particular characteristic, or set of characteristics, that causes them to be regarded as a group, more or less precisely defined or designated; class; category:

But the example provided is, "a criminal of the most viscious type," which applies the definite article to the word, indicating singularity, and not plurality. So maybe it could be technically correct to write "type of tools," but it still seemed not-normal. So I went to my constant back-up position of objective assessment of language usage: Google n-grams. For both the various permutations of pluarlity of the original phrase, "type of tools," and the more general phrase, "type of things," I had the same result, namely that "type of tool" (and "type of thing" - red line) was far-and-away more prevalent than "type of tools" (or "type of things" - blue line). Even "types of tools" ("types of things" - green line) was more prevalent.



Is the pattern different in Spanish? I tried the same permutations, but in Spanish, and found that "type of things" (tipo de cosas - red line) was WAY more prevalent than any other permutation, with insufficient numbers of exemplars of "types of thing" (tipos de cosa).



So, yeah, it seems that the inherent logic of what is and isn't a collective noun between English and Spanish is different, and this particular writer was likely working from his instincts of whether "type" worked as a collective noun in the same way as in does in Spanish. The simple fact that it doesn't is also likely a lesson that was never covered in his English language lessons, or likely wasn't reinforced. Regardless, what started as a bit of a mental puzzle was resolved in one of the more neatly packaged means that I have encountered.