subscriptions payments
Is it possible to pay two different subscriptions with two different credit cards?
No, that is not possible.
You can have a credit card / debit card on file and an Apple Account balance.
Your default payment method will be used first by Apple when you need to make a payment.
If you have set your Apple Account balance as your default payment method and you have a CC / debit card, you pay from your default payment method.
If you have 2 CC, and you have set one CC as your default payment method that will be charge by Apple.