It suggests to me that two writers made it up!  If you read it, it makes it clear whose genealogy it is.  To suggest that one is Mary's is ludicrous.  I'm surprised you go down such a line, since you obviously don't believe it yourself.

I was simply quoting what a number of well-respected scholars have suggested - including some Jewish scholars.  I think I'd rather trust their ideas than those of us with little or no in-depth knowledge of the ways that these things were done.  At the same time - bearing in mind the common claim by those who refute the Bible, the comment about whose lineage they were might have been added later (it is interesting that this kind of suggestion is never entertained by people who want to knock the Bible: later additions are only ever the more contentious issues that people nowadays dislike the bible for - and anyone with any nous knows that there are some copying errors in certain copies of the material - hence the various 'alternative' readings).