One filler team can beat other filler teams.
Also, don't underestimate xerxia, they can beat Brazil teams, Edward Gaming is yet to prove themselves against some really good teams (best they fought against was Nth). Zeta is suffering from the loss of TENN.
They also have upset potential. you cannot forget optic and Xerxia still have a 2-2 score. Their match against Liquid and FPX was also very well played and in the end it was just Liquid's day in Iceland leading them to go out in groups.
I am not saying they will make it out. There is obviously a huge "if" but they did make it in previous champions and they have not looked very weak either. If they get a lucky group there is a 50/50 chance of them qualifying for playoffs as the second seed.