Carthaginian guests

[Omanes Alexandrapolites]

Hi Javolenus Priscus

are these uninvited guests hitting my local economies?

As long as you are not at war, the troops hanging around in your province shouldn't be slashing and burning the land as enemy troops would. This can be seen as the factor known as "devestation" on the settlement details scroll.

And are they trying to provoke a war?

I don't think the AI is really clever enough to actually think that intelligently, so I would be inclined to say no. They probably are there due to a path finding problem. Either that, or they are preparing to make a move upon your nearest city (this sounds unlikely though, since you claim they haven't moved around for quite a few turns).