There are no 'easy' wins in the NFL, and I am fully confident the Cardinals have the Seahawk's full attention. That said, this Cards team is not really any better than it was in week 7, and with Mathieu out, it's in many ways worse. Sure the Cards have a great winning percentage, but:
1. They've feasted on the cream-puff part of their schedule
2. They've hit opponents that were hard in other parts of the year at exactly the right time when they were the most vulnerable (like the Colts)
Yes the Cards did beat the Panthers, but that was in Arizona, and the Cards play much better in Arizona than on the road (if not to the degree of the Saints). Finally I note that winning or losing in Seattle has relatively little to do with Arizona's playoff chances (Carolina winning or losing matters more).
So I fully expect a dominant win, but I never expect an easy one.