That video is 3 years old and they are lightweight piss ants. They barely drink it all. The only thing I can give them credit for is that they were on the grift train before most.
They were normal in the statistical sense on intake before they embarked on their challenge. It's easy to spot because after only a few drinks they were severely impaired, a regular every day drinker, above 3 units of intake wouldn't touch the sides that early on. Send help, for sure, for their useless careers.
EDIT: If you are gonna do a tribute, do a Hunter S. Thompson breakfast and do it properly, for fucks sake.