Sorry, I'm not sure I follow your argument. I understand that there are many people going by the name of Andrew Robertson but my basis for this proposal is that anyone searching for Andy/Andrew Robertson will almost certainly be looking for this person (WP:PTOPIC). Indeed, anyone saying "Andrew Robertson" in a Glasgow pub will almost certainly be referring to him! The coverage of his rise from amateur to international football in less than a year has consistently been covered in the Scottish press. He's one of the most talked about players in Scotland at the moment and is expected to be the first choice left back for the national team for several years. Most of the other Andrew Robertson articles on Wikipedia are stubs and a quick google  shows that he is clearly covered more than any other Andrew Robertson.