(Psi)SeveredHead
Adventurer
This isn't about what's good for the game at your table. It's about what's good for the town. If I'm a town elder... I don't let merchants with "bodyguards" come into my town. Do you think I'm going to for fall for the banana in the tailpipe trick yet again? Nope... not me. If the merchant with bodyguards wants to gain my trust, he can do so by accepting that I don't let merchants with "bodyguards" into my town... no matter how nice their sample wares are.
That's a great way to starve, or at least lose out on luxuries.
Back in the Anglo-Saxon days, a person living in central Britain could get fresh fish, brought to him by merchant. Fresh meaning one day old or less, not literally fresh. (Well, that's what I read. Take with a grain of salt, this was more than 1000 years ago.) Of course, to carry fish that far the merchant has to travel a long distance, on roads frequented by bandits, warlords, or both. In a fantasy setting, maybe there are monsters on parts of the road, whatever part isn't patrolled and requires you to pay tolls.
Either the merchants hire bodyguards, the merchants learn to defend themselves, or there are no merchants.
A few locals might dislike merchants, but everyone else wants their fresh fish, religious relics, magic items, newest fashions, rare wines, and whatever else the merchants are bringing them.
Carrying a few samples makes sense if the stuff you're carrying is valuable. The wizard could carry samples of magic items, the fighter could be carrying pepper or pipeweed...