2. The second reason that they cannot be built together is that Nukva has to be built by Zeir Anpin himself, and this is only possible after he is already repaired and fit to build her.
…through her Mental Powers… i.e. through Netzach-Hod-Yesod of Zeir Anpin, which build Nukva as required to suit her function.
…so that they can repair all her different levels as required… There is no need for symmetry with Zeir Anpin in this. Quite the contrary, Nukva requires her own unique repair to suit her intrinsic structure.