Yes, it is easier for them to compare apples to apples. Not wonder what an 1150 PSAT NMSQT (not sure why OP didn’t take the PSAT 10 or PSAT 8/9 instead?) taken with all kids going to public and private vs an SSAT which only compares same test/same applicant group to competitive private schools.
I would say OP should talk to a guidance counselor, regardless, before making important decisions, rather than relying on a message board.