I think this may be matter of perspective. You are right that the schwab master accounts on the sheet you posted use the swift codes when you send money by international wire. However, if you live in one of the countries where schwab maintains one of these accounts, you can send the money through the account to your schwab account without using the swift system. Schwab reports my money as funds wired in but they do not charge me a fee.
I have assumed the purpose of the accounts is to let customers avoid the swift system and allow them to save money on wire and exchange rate charges when they send money to schwab. Of the brokers, I looked at schwab was the only one who had set up this type of system.