MODERATOR’S NOTE:
Let’s not lose sight of the fact that the OP asked about Washington and Lee and Davidson. So please do not conflate with what is “recommended” for other universities. There is an entire thread on the general topic to which users can contribute:
http://talk.collegeconfidential.com/college-admissions/2027962-sat-subject-tests-are-not-truly-optional-for-middle-upper-middle-class-applicants-at-elite-colleges-p1.html