remodel backsplash issues

I installed Giallo Vicenza in a home that had a tile backsplash. I did not bid on the backsplash and (http://maplered.com) it turns out that their previous Counter (http://GialloFiorito.com) s were about 1/2 thicker than the Granite (http://tanbrown.org) . Would ya'll normally shim up a whole job to meet the previous backsplash or is that something the homeowner should hand (http://maplered.com) le?

DSpells