According to dialogue, one of them buys goblin related stuff, and the other non-goblin related, and they don't interject with one another with the exception this one item. If i were to guess, it should only be on the "non-goblin related" list (all goblin items have a tribe name in them, except for "high priest" items).

And yeah I know it'll be some time before someone can even be affected by that, but better fix it in advance, if it needs fixing, I think.