highly unlikely since the event is from 9 until 2am! I also heard 10 to 10:30 start of his set which makes sense since this would mean a 3:30 to 4 hrs. set.
So rumor has it that Arc management is still trying to work things out with the Visa and immigration so Marco V can enter the country.... let's just keep our fingers crossed
Armin is not spinning for 6 hours (unfortunately) on Oct 1. It's from 9 until 2am and he has Olivier Berge opening for him. So I would expect a 3hrs. set max.