Should a bank statement line only contains either Account Payable or Account Receivable?

I am having a discussion with my Chinese staff. In China, the role of Cashier (operates the bank) and the role of Accountant (operates the book) are strictly separated. When the Cashier enters the bank statement, the Accountant doesn't want the Cashier to select any accounts, like office rent, tax payment or office supplies.

So I proposed that when the cashier enters the bank statement in OpenERP, she only selects Accounts Receivable for a credit and Accounts Payable for a debit. So the Accountant has to make sure there is a purchase order/sales order/expense request (or creates one) and reconciles it. This means also make an invoice for e.g. paying the rent or paying taxes.

To me, this seems like a good approach, the cashier only needs to have access to three accounts (bank/AR/AP) and we have a clear tracking of all bank statement lines because each has a document attached (an order) with an approval process. Are there other people do like this? Any reason why this would be bad from an accounting principle point of view?