The decision to flee or engage is not part of the engine, but rather due to the scripting within a particular mod. In order for me to determine whether there is a problem, or if by mod design, the next time you think the opponents are fleeing wrongly, take a save at sea and send it to me at chezjfrey@hotmail.com. Also indicate what game: COAS, ERAS, GOF 1.2, etc.