Some transports were specifically and intentionally comprised of working Jews and were admitted as a matter of course upon arrival. Of course many of them were sick because of brutal treatment in transit. Indeed, the vast majority of Jews arriving at Auschwitz were sick including most "working Jews."
Because Mattogno aims to deceive he does not tell the reader any of this critical context when he discusses this document.
Regarding this specific transport, Mattogno provides no original primary source for it so I cannot do any research on it. He instead cites an obscure Polish secondary source (Blumental, 1946), which basically makes this hearsay by history standards. But even if Blumenthal was right, and Mattogno is accurately quoting Blumenthal (rather than cherry picking or misleadingly quoting him), this could have been one of the pre-curated transports of working Jews to which I am referring.
That there were apparently no children in this transport, but only men and women, is an indication that this transport was curated as a "working Jews" transport, rather than a transport of a bunch of random jews that would face a typical selection process.
Even from the information Mattogno provides, we can assume this transport is about working Jews. For example, I quote from Mattogno
"Of the 750 male prisoners, only 424 were found to be capable of working,
while the remainder of 326 prisoners were designated as unfit for work in the planned assignment to Labor Camps Buna and Neu-Dachs.
Of these 40% not-fully-fit-for-work prisoners, some must be placed in prisoners ’ quarters as well as in the recovery barracks . . .
Of the 750 female prisoners, 80 prisoners were designated as unfit for work,
which amounts to about 10% of the entire transport."
Notice the terms "unfit for work in the planned assignment" "not fully fit for work" and "recovery barracks." This transport is all about working Jews, and attempts to help them recover for labor. The fact that they are ill is unsurprising because almost everybody including working Jews would be ill after that transit. As I have said repeatedly the Nazis had to admit ill Jews as "working Jews" to meet their labor quotas. Because of how appallingly they had been treated in transit and in ghettos, etc, "able bodied Jews" often really meant the relatively less ill ones who were nevertheless still ill. The Nazis did, as we have discussed, provide limited health care to these slave laborers to enable them to recover and work.
Also note the perfectly symmetrical character of the transport - 1500 people, 750 men, 750 women (no children). This is obviously a pre-curated transport of working Jews meant to fulfill quotas of labor needs.