Quote Originally Posted by Silverhawk
From my latest patched game, this is no longer true. Merchants on resources will "attack" other merchants who are adjacent to those resources but not trading. I can't say if that means they'll attack well off resources, as I've not seen that (and tend to play merchant-light games as England). Lost a 9-star to a lucky 5-star venetian merchant the other day like this though, I swear those venetian merchants have ungodly luck...
Hmm... still holds true in my game (after patch). AI merchants would ignore my merchants off resources.

On a different note, there is a suggestion to build merchants in a city with merchant guild. I have noticed the following:

1. High level religious buildings tend to spoil merchant qualities
2. Law buildings enhance merchants in a sense that they do not get negative "crook" traits. I have stopped training merchants in cities that do not have at least a city hall.
3. High level market buildings + merchant guild tends to train merchants with high rating (I have seen +5 skill merchants coming out of those).