Since this point was not mentioned I will do it .
Arranged Marriages are a marriage of convenience mostly - Both of them can focus on whatever they want to do and then when the time is right , Boom it happens. Now I am not saying this perfect. But anyone who is out there going night after night , working hard at improving his game skills , soaking up vast amounts of theory on seduction , female psychology , persuasion and covert hypnosis. Would agree that all the valuable time can be spent doing something more constructive. And the chances that relatively inexperience in relationships would translate to reduction in the number of std's and making sure that she is a virgin (important to some folk). Not to forget members of british royalty and other royalties throughout the world have very close marriages , to preserve wealth, and the reason why members of royalty are so !^%@#!# up 🙂
Sure scientifically speaking the percentage of incurring genetic errors between people with very close dna sequences is extremely high, however there does not exist any controlled studies that can draw a conclusive conclusion, moreover I foresee that in the future, if families do insist that people of close blood ties get married , they atleast seek genetic counselling , or maybe genetic medicine will be advanced enough to make sure that their kids are healthy.
And if you are the type of that person who only respects skill, then GAME ON !