Well that was just a simple example with round numbers. In reality you will have thousands and thousands of such transactions all going to seemingly random wall

Well that was just a simple example with round numbers. In reality you will have thousands and thousands of such transactions all going to seemingly random wallets with random amounts, and then to ten thousand different ones, back and forth. They will look like real transactions too. You can't possibly track something like that. Most wallets don't have any names attached to them. And even in this simple example you don't know who F, X and Z are and how to find them. They are just wallet numbers.