Issue : 
With the current AI, when you have the advantage at command point even at 5 fleet against one, the AI get wiped out easily because usually the fleet are scattered.


Fix : 

For example in Civ IV, the AI sacrified unit to wear off a powerfull opponent until it killed it. An AI in ES2 with such a behaviour would concentrate its fleets and send them against a more powerfull opponent. So the change in the current AI behaviour would be to make it wait and concentrate its fleet before attacking a powerful system or fleet.