It doesn't take away the fact that ancient Macedonia was Greek untill 500 AD, it was as at that time Macedonia was over run by local feral "tribes" including the feral Romans, where Greeks had to instill manners into them - well known thieves.
It is correct to say that current day "slavic" Macedonia DNA's is vastly mixed. However, I am certain that southern Macedonia is vastly untouched as local priests brokered deals with Ottoturkfilth the poeple would keep their culture but remain under Ottofilth rule.