I feel that these terms porneia and fornicatrix refer to prostitution. It means to come under the “arches”. That’s where the prostitutes hung out and you could find them. Don’t bash me, but I feel it was written more about women selling the goodies. Men always had multiple wives and concubines. Only in the qualifications for elders does it possibly say husband of one wife. I only say possibly because they translate it to read in a manner suitable to them. So more than one woman is ok if wifey is good with it and you can afford it.
Side note: Speaking of arches…this is also why I feel USA is Babylon the Great, the great harlot, because of what is the Gateway to the Western culture in St. Louis, Missouri “The Arch” and the Washington Monument “erected” in DC.