I would love it if I could over-withdraw money from my bank account by having someone on the other side of the country take out money from my account at an ATM at the exact time as me, due to the fact that the bank's storage system was eventually consistent, but that's not the case.
Pretty sure that when it comes to write transactions, such as bank transactions, you want them to be executed on a source of truth with enforces consistency, not eventual consistency. Any client software should not be trusted -- especially one written by a silly programmer who uses a cache as the source of truth.
