The grantor‘s index to local land records usually only contains the name of the first grantor on a deed–not matter how many names are listed as grantors (sellers).
These indexes were created by the records office as the deeds were recorded and items were not necessarily recorded in the order in which they were executed. Indexes are not always exactly alphabetical either. They usually group grantors by the first letter of their last name. The first name may or may not be indexed.
Always look the index over before using it and concluding that you have “search the whole thing.” Different counties may keep their indexes in slightly different ways.