The source name and Xero account are different things
A checkout can report “Stripe”, “PayPal”, “card”, “BACS” or a custom method. That label identifies how the customer paid; it does not define the chart-of-accounts code. ClearCommerce stores a mapping so each company can choose its own destination.
Mappings remain store-specific
Two stores in the same company can use different payment methods or account structures. A profile can therefore keep the accounting treatment local to the store without changing the underlying connector.
Payment handling can carry a behaviour as well as an account
A method can participate in a daily summary, accompany an individual paid invoice, remain unpaid or be skipped where the workflow requires it. That design is what makes BACS and card orders capable of different outcomes.