don't trust the power graph. on aggressive ai, it is very hard to keep up on military. therefore, if you want to attack, you have to priorities defense/attack. the ai's power graph always looks big but they tend to stack units evenly across most cities, so a big stack can take out many cities. on the other hand, you will have no problem in just letting a warrior defend those inner cities, so consequently what little power you do have can be concentrated on where it's needed in attack or defense.
siege weapons are also a big factor. they don't contribute a vast amount to the power graph but can severely weaken the opposition stack making it an easier target. don't neglect siege weapons, they are vital.
some opponents (Monty is famed for this) will build a gigantic stack in every city of rubbish and outdated units like jaguar warriors or longbowmen. despite the fact that at the right time they are effective but he often still has them when you are charging about with stacks of riflemen, grenadiers, cannons and cavalry. These will obliterate his puny force in seconds, despite his giant power graph.
Power graph, useful but not reliable.
siege weapons are also a big factor. they don't contribute a vast amount to the power graph but can severely weaken the opposition stack making it an easier target. don't neglect siege weapons, they are vital.
some opponents (Monty is famed for this) will build a gigantic stack in every city of rubbish and outdated units like jaguar warriors or longbowmen. despite the fact that at the right time they are effective but he often still has them when you are charging about with stacks of riflemen, grenadiers, cannons and cavalry. These will obliterate his puny force in seconds, despite his giant power graph.
Power graph, useful but not reliable.