First of all, I don't think that link was them being serious. Falco players have a fair option of how to handle that situation. Plus....yeah, look at it XD
Second, there's the ledge grab rule effected in Brawl, and you would need those ledge grabs (as well as godly manuvering and godly DI) in order for even having a chance to have 4 stocks (and this is to the person doing the camping)
The only legitimate way for both players to have 3 stocks is for either of them not playing the game at all.
I'm sorry Kawii, but it's totally impossible. And if there was such a tournament video of it, the TO has not been doing its job.