When will this kind of matches be corrected? You say that siblings may be matched, but brother/sister (image 1) should be impossible or even total strangers of opposit gender (image 2).
Empty fields seems also to be a sourse of correct matching since I have had only same gender and empty fields yielding high percentage in matchings.
Since Smart Matching is on server side it would be easier to correct these kind of bugs than new versions of FTB and other new functionality. Next improvement of software must be the Smart Matching and not new features users are not asking of. One year ago Smart Matching worked better than now. How about restore that version of SM.