a mandolin sound nothing like a guitar if i knew how this worked i could make some mandolin sounds and model (after i get my pc fixed)
That a mandolin sounds "nothing" like a guitar is an exaggeration. Bottom line, I want to avoid having too many instrument sounds as an issue of both datablock limit and filesize. A mandolin sounds enough like a high-pitched steel-string guitar that it's probably redundant to have both a "guitar" soundset and a "mandolin" soundset. Likewise, if someone made an old-fashioned lute model, it would probably use the guitar soundset as well.
All this depends, of course, on what instruments anyone actually models. If someone made a mandolin you
could maybe convince me to add an extra soundset, but for now it's not necessary.