I think the evidence is in the command to marry, be fruitful and multiply. Else what is the purpose of having marriage, whether monogamous or plural? Further evidence is in the fact that these women are regarded as "wives," rather than "wards," or "adopted."
Nice dance hana, but no dice. The concept of "spiritual" marriage, as applied to many of the woman to whom Joseph was sealed, implicates a true personal relatinship only in eternity. It has no necessary implication (and was not understood at the time to imply), normative earthly marital relations. I am not here speaking of the unmarried woman Joseph married, but only the case of sealings to already civilly married woman.
In other words, your "evidence" is no more than your own subjective benefit of the doubt given to your own position, and you have little substantive understanding of LDS doctrine, not only in this area, but probably in many other areas as well.
Still further evidence would come from the fact that Emma Smith would not be anticipated or likely to have difficulty with the concept were sexual relations not involved. They would not then truly be "plural wives."
In other words, not a shred of historical, documentary evidence from reliable historical sources showing that these purported polyandrous relationships (to the degree they were even relationships that went beyond the sealing event) ever involved sex.
Thanks, I needed that...
The face of sin today often wears the mask of tolerance.
- Thomas S. Monson