You make many fair points, but what you say is HIGHLY anecdotal and has a lot of false information. When making a list like this, it's not as simple as 'he is good at clutching and winning rounds so I will throw him top 6', a lot of things have to be considered, compared and contrasted to come to a fine list. Xyp9x is a great player, of course, but he is not deserved of a top 6 spot. He had a slow start to the year, and has only started to REALLY pick up his numbers into the latter half of 2018. He is not the 'guy winning rounds for astralis', no, all 5 of them are, that is why they are so good. Gla1ve, one of the best IGLs we have seen with his fragging potential, Device, the second (some say best) player of the entire year. Dupreeh, who is contrary to what you say, the actual Entry Fragger for Astralis and my fucking god does this man do a good job. Xyp9x is absolutely not the guy winning all the rounds, just because he is famed for making rather intelligent plays, doesn't mean he is objectively the best clutcher and round winner. Being good at very specific things like that is easy to point at and go 'wow he is good' but there is a lot more tough work that other players have been doing around him.
Xyp9x is good, but he's a top 15-10 player for this year, definitely not a top 6 in any stretch of the imagination.