navi might be the only current good team they did not face recently (although BIG 2-0'd navi @ EPL and NaVi is holding their top5 spot by struggling against CIS t2-t3 Teams) , and dont get me started on NA teams.
they beat faze three times, they beat g2 (which i definitely would consider a top3 team in the online era) with a 2 map deficit and a 11-4 half on the decider map for G2, they beat vitality, they beat fnatic, they beat complexity twice, they beat mousesports
alone mouz, faze, fnatic and g2 were all top5 teams at the beginning of the year. it is not BIGs fault if they do not perform. BIG beat everyone they got matched up to.
and astralis beat themselves, its not BIGs fault either they dont have a complete roster and its also not BIGs fault they went 9-12th at DH Masters.
as i said, nobody should overhype this but also nobody should take it away from them. BIG is looking the most dominant right now and this is by no means the weakest top1 placement in hltv ranking history.