@BluePaul
You could solve that by not making groups at all.
Give all 8 persons a number.
If person 1 gets trough, he buys for person 1, 2, 3, 4, 5, 6.
If person 2 gets trough, he buys for person 2, 3, 4, 5, 6, 7.
...
If person 8 gets trough, he buys for person 8, 1, 2, 3, 4, 5.
This way everyone has an equal chance and no one had to be drawn beforehand in the unlucky group of two.
If you all are in direct communication you can quickly inform when one has tickets and everyone starts to try for the remaining two.
I don't believe that they drop the three headliners in one week... That doesn't roll out Green Day, but makes me wonder if they wouldn't be announced earlier, because, if NOS Alive has them, everything makes me believe that they'd be authorized to announce.
If it's not Green Day, it's problably something that didn't announce for festivals yet or Sabrina, who has only been announced for Primavera Barcelona. The last option is two slots for co-headliners.
It is, every chance though that photo was correct at some point though with BST not in the frame or something. I'm absolutely sure that Fred, Olivia and one of Rihanna, Stevie and if not Fender would have been in the frame. I messaged my friend ages ago when the odds first appeared saying I think Fender might do it hence I put a bet on at 6s.
Also, even Mcfcok believed originally although not totally solid that Olivia was the Friday. I would hazard a guess that she was the Friday and with Fred pulling out probably she could move to the Saturday which was an option anyway and more so with the BST booking. That's the theory. I think Fred would make more sense on the Saturday for the festival if they got Rihanna to split then up but I guess it comes down to more than that.