First, no applicant is a National Merit Finalist when s(he) applies coolege since National Merit Finalists come out after application deadlines.  We only have National Merit Semifinalist applicants and no National Merit Finalist applicants;

Secondly, for academics, GPA is more important than SAT if we want to choose the more important one in the two.  The best is great GPA and great SAT, the second is great GPA and so so SAT, the worst is great SAT but so so GPA.  Though I personally think SAT is a comprehensive test and reflects more of the academic capability of the student than GPA since GPA test materials more close to the courses the students took.  But GPA reflects 4 years of high school learning and SAT just a couple of tests and 2400 may be a super score from multiple tests.

Third, test score is a single one, though is the most important one, measurement of applicant's abilities.  It's only one dimention of a multi-dimentional applicant.