So we have a Machlokes. Sam2 says assur, and the Ohev Yisroel (and my mother) say (or represent) “Torah Hi”.
Presumably, the Ohev Yisroel was directly addressing the claims that it had other origins (otherwise his words are rather misleading). The small quote I saw here was not that it didn’t have other origins, but that since it came down from previous generations, it is correct. Sam2 says he knows better than the previous generations.
While I don’t have the knowledge that Sam2 is representing with his viewpoint (namely, that there is no legitimate source before 1800 or so, and that previous great ones and previous lesser ones were misinformed at best), Sam2 hasn’t proven the negative at all, let alone sufficiently to make him more credible than even my mother…