I tried to read the 40-page section relating to Newton, but the editorship is quite hopeless.
First there are some haphazard extracts from letters to Huygens. The editors maintain that "in these letters ... Leibniz ... argues that all motion is relative" (p. 307). But this is not true. There is no argument. The relativity of motion is merely asserted. "I have reasons" (p. 308) to reject the bucket argument, says Leibniz, but he does not present these reasons, nor are there any references to help us. That is not what I call an argument; nor does it help us understand why on earth this letter was selected for this collection.
27 pages are devoted to Leibniz's half of the Leibniz-Clarke correspondence. No excerpts are given from Clarke's letters. Much of Leibniz's letters are paragraph-by-paragraph replies to the specific arguments raised by Clarke. Since no sane human being would want to read only the Leibniz half of this correspondence, its inclusion is virtually worthless.
Another selection is an 8-page polemic "against the revival of the qualities of the scholastics." The editors misunderstand it entirely as an "attack against Newton's theory of universal gravitation, comparing it with the occult qualities of the Scholastics" (p. 312). It is simply nothing of the sort. In fact, despite numerous references to scores of scientists and philosophers, Newton is never mentioned once in this entire essay. Let us look at the passages that prompts the editors' confusion. Here is one:
"It pleases others to return the occult qualities or to Scholastic faculties, but since those crude philosophers and physicians [see that] those [terms are] in bad repute ... they call them forces. ... these persons imagine specific forces, and vary them as the need arises. They bring forth attractive, retentive, repulsive, directive, expansive, and contractive faculties." (p. 313)
Who in their right mind could take this for a description of Newton's work?
Another example: "those who have shown that the astronomical laws can be explained by assuming the mutual gravitation of the planets have done something very worthwhile, even if they may not have given the reason for this gravitation. But of certain people, abusing this beautiful discovery, think that the explanation given is so satisfactory that there is nothing left to explain, and if they think that gravity is a thing essential to matter, then they slip back into barbarism in physics and into the occult qualities of the Scholastics." (p. 314).
Again Newton cannot be the target since he explicitly disavowed this very proposition. Nor do Leibniz intend him to be the target: it is crystal clear to anyone capable of reading (which apparently excludes our editors) that Leibniz is saying that Newton made a "very worthwhile" "beautiful discovery" that only "others" have "abused."