On the Mishnah, we are dealing with a variant reading.
(30) Threads, or according to others, denars in value. Another reading is ( ,uchr ) ‘damsels’, instead of ( tuchr ) ‘ten thousand’; i.e., it was woven by eighty-two young damsels.
http://halakhah.com/pdf/moed/Shekalim.pdf
Marshall quotes many more traditional sources beyond the Mishnah. And why is the Jewish tradition all of a sudden "unreliable"? We would not know nearly anything of the Judaism of the Second Temple period if not for it.
Firstly if we’re going to argue from what can or cannot be imagined then we’ll be the equal of the Rabbis of the Talmud who contemplated such heavy questions as How many men can hang onto the skirt of a Jew? (they had an answer) or Whether Jesus obtained magical books from Egypt (they had an answer) or that the term Rabbi was not used til after 70 A.D. and on and on.
Like I said Jewish rabbinical tradition is like sand that one has to sift great quanities to find a few flecks of gold.
Just as the quote from the Mishnah is the opinion of some Rabbi. How accurate is it? Everything the Talmud opines must be viewed as conflicting rabbincal opinions and that makes it unreliable.
Yes, we have two different reading, if the Marshall quote is the more accurate then what is being said is that maidens (virgins) wove a Temple curtain twice a year.
Would that be a temple virgin cult? Does that support Mary as a temple virgin or such? No.
A way too much is being read into a few traditons which are not “suddenly unreliable” but have been since Jesus’ day at least.
I opine that you haven’t read much of the rabbinal writings.