(Mishnah): Any Get with a Kusi witness on it is Pasul, except for Gitei Nashim and Shichrurei Avadim;

A case occurred in which the witnesses on a Get Ishah were Kusim, and R. Gamliel ruled that it is Kosher.

All documents that enter (were written in) Nochri courts, even though Nochrim signed them, are valid, except for Gitei Nashim or Shichrurei Avadim;

R. Shimon says, even these are valid; they are Pasul only when done by commoners.

(Gemara): [Kusim] are suspected about money, and they are disqualified for monetary [documents]. They are not suspected about Arayos. Capital testimony is like testimony about Arayos.

Question: If so, even if both [witnesses on a Get] are Kusim (it should be Kosher)!

Answer: That is different, for they are not expert about fine Halachos of Gitin. (We are concerned lest there is a Pesul.)

Question: If so, even if one [witness on a Get] is a Kusi, it should be Pasul!

Answer (R. Avin): The case is, a Yisrael signed at the end.

(R. Yosi): [Our Mishnah] is like the opinion that witnesses may sign not in front of each other. However, according to the opinion that witnesses may sign only in front of each other, even if the Kusi signed at the end, it is Kosher.

(R. Ila citing R. Yosa): It is like the opinion that witnesses may sign only in front of each other. However, according to the opinion that witnesses may sign not in front of each other, even if a Yisrael signed at the end, it is Pasul. (Perhaps the Kosher witness signed at the bottom, for he thought that someone greater than himself will sign with him, and in the end a Pasul signed with him. - PNEI MOSHE)

If four witnesses signed on a document, and the first two were found to be relatives or Pesulim, it is Kosher, and the testimony is sustained through the others.

Question: It should be as if the testimony [the Kosher witnesses' signatures] is distanced from the document, and it is Pasul!

Answer: You cannot say so, for R. Yosa said in the name of R. Yirmeyah that Pasul witnesses are not considered distance of testimony. They come only to be Machshir the Get.