In his text 此生或彼生 Lu Xun takes apart a proponent of literary Chinese (named, I think, Wang Maozu). Wang had attempted to argue the superiority of Literary Chinese by pointing out that
could be recast in Literary Chinese as the reduction
Wang’s argument immediately struck me as somewhat disingenuous, since several 一 and 是 can be omitted in colloquial Chinese.
Lu Xun responded with the valid criticism that 生 in Wang’s reduction was ambiguous and could denote 學生，秀才 and 這一世/來生。
While I believe that f.e. 孔子家語 offers many examples of Classical Chinese being read ambiguously by the Ancients, I wonder, how hard it would have been for Wang to make a better argument for this single case.
Could Wang simply have said
to make his meaning clear without lengthening the phrase?
Is there another, less ambiguous, option of equal or even smaller length?
I suspect that most 此A彼B patterns involve A and B verbs [此起彼落、此呼彼应], not nouns. Though 此界彼疆 might be an exception. But perhaps the 此A彼B pattern is not even the smartest way to go.