Let me screw up your thinking even more. It has been almost a year since I read thru the rng scheme used by both FT and PS, and others, but the concept of a deck doesn't work like you might think.
During any hand all the cards in play must be unduplicated and fit within the definition of a deck. But the available cards (i.e. the 'deck') is continually shuffling, and get this, it contains as many cards as there are in play at any instant on the whole site!.
If the site is showing there are 5000 tables playing, then there are 5000 Aces of spades available at any instant for your table. If there is an Ace of spades already in play at your table, and the dealer picks one of the other 4999 Ace's of spades, it is discarded and another card is picked. The shuffle is done at a pace measured down in the quantum time realm.
For all but the most theoretical of physicists amongst us, the reading of the method, which doesn't even go into much detail, is a headache producing, mind boggling nightmare. Trust me, I read through it once, about a year ago, and still suffer the effects.