That might be a hard call to make in some cases, since some strings do many things well. Where would Spiros go, for instance? They work great for pizz, are commonly used for arco. Conversely, Olivs are somewhat marketed as a great arco string, but there are quite a few folks pizz'ing on 'em (pardon me!
).
As always, I'm sure there will be lots of lively discourse here on strings. The ultimate love/hate relationship!