I've boiled this down further, I think -- into simpler terms, for reference:
- Alice wants to Pay Bob 0.5 BTC
- Alice sends 0.2 BTC to Deposit Address A, followed later by 0.3 BTC to Deposit Address B
- Coin Z (0.5 BTC), somewhere entirely else, is sent to Bob and is entirely unconnected to Alice's deposits
More ...
and most importantly::
- Coin Z went through 200+ separate CoinJoins over a period of 6 months
- The Coin Alice Deposited at Deposit Address A, later on participates in a CoinJoin
- The Coin Alice Deposited at Deposit Address B, participates in a separate CoinJoin 2 days later
- Alice's Coins are CoinJoined 20 or even 200 times before they even make their way back out of the mixer