I want to have one cash clearing account across all bank accounts

Summary: I have a client with hundreds of bank accounts and they are looking at the option of one clearing account across all bank accounts and not one for each bank account

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I have a client with hundreds of bank accounts and they are looking at the option of one clearing account across all bank accounts and not one for each bank account. I know best practice is to have one bank GL natural account for each bank account for cash and cash clearing but we want to know if anyone has not followed this approach and what was the disadvantages and advantages of this approach.