For adhering veneers I will use a stronger mix...it depends on the type of stone...and more often than not tile glues are being used these days.
I'm mostly experienced with dry laid walls, as well. But I've often wondered why not just use adhesive on the veneer work if you are working with a consistant (not irregular) foundation.
We can get most any stone in a venneer form now (I'm talking "real" stone not "pseudo-stone").. with premade corners etc. ... So it would seem easier to just use adhesive, especially if you wanted a "dry laid look."