If you know their name, you can target them by name. If you know one by sdesc only, and don't know their name, you can target that one by a word in that sdesc. If you know that two of them share similar sdescs, but the one you want to talk to wears a certain thing that the other doesn't wear, you can try this *TOTALLY OOC TRICK*:
examine tressed's kilt
If it returns "He isn't wearing anything like that"
you can then
examine 2.tressed's kilt
and if the second guy is wearing the tell-tale kilt you can then
tell 2.tressed (passing the sids over) Here, now leave me be!