If you are interested in Big Law, you have to shoot for the highest ranked school you can get into. Unless things changed drastically since I was involved in hiring for a Big Law firm, the number of flybacks/callbacks we would give varied greatly by school and there were a limited number of schools where we would even recruit. Geography also played a role. We were NYC based, so in addition to Columbia and NYU, we would recruit on campus at Fordham, Cardozo, Hofstra and Brooklyn Law. I am not sure a Chicago, LA, SF, DC or Boston firm would recruit at some of these schools. Conversely, my “territory” was California since I am UCB Law grad, and we recruited at UCB, Stanford, UCLA and USC only back then even though there were/ other fine law schools in California. Now some of this regionalism has gone away with all the big law firm mergers with regional offices doing their own hiring.
Separately, if you were going to a top 10 law school and you were in the top 25% to even 50% of your class, you were legitimately in play. For lesser law schools, you had to be in the top 5% to 15%. Our summer associate classes were predominately Harvard, Columbia, NYU, Cornell with a sprinkling of Yale, Stanford, UCB, UChic, UVA, UMich, G’town, Duke, Northwestern. It was hard to get students from the Cali schools to leave Cali!