aggro between enemies

Is there a way to aggro groups of enemies so that they fight each other?

Some enemy groups are natural enemies of other enemy groups. - You can see this a lot in the Jade Sea area of factions. There are WiK mobs that will fight regular mobs if they get to close to each other. There may be other cases where enemy groups will fight each other that I can't think of ATM, but if they don't have that "natural aversion" for each other, you won't be able to get them to fight each other. They'll just join forces and go after you and your party.

As Kook said, there are some mobs that will fight against eachother, but 99% of them wount.
In FoW theres quite alot of mobs that will fight eachother.

No Im afraid there is no way to actively do this. As others have posted, various groups of enemies will agro on each other and start fighting... but if you agro any group and try to pull them to a differnent one, you will end up with both groups agroed onto yourself until you are dead... only then will the 2 groups start beating on each other.

though they wount normally start killing eachtother, eaven after they killed us