Well I was once chased by 6 wogurs, a pack of trollies, and 5 nymphs. Since I ony had three low-level characters it was a excruciating hit and run fight.
It's a bit disappointing that monsters don't fight each other but at least they blocked each other's paths.
Btw, this constitutes as one of the more major faults in the game. Some monsters clearly wouldn't follow you around.