3rd Gen Did you trade with any of the NPCs?

It depends on his trade, if it's a pokemon that needs trade to be evolve or pokemon that I can't find in my region, I will do the trade with the NPCs
but I'm sometimes lazy to check around so some of them left untraded.

Mr. Mime, Jynx, Farfetch'd and Lickitung can be only caught by trading with the NPCs, so it's definitely a yes, or more like a must, haha!