We use Marriott a lot and have one visa card set-up in their system and our reservations are guaranteed to that card. When we check-in we occasionally use a different card for part of the stay as sometimes a receipt is needed in my wife's name.

Express check-out can work with two cards provided you deal with front desk staff who are competent.

Just remember that the hold against your first card may not come off until a day or so until after check-out!