Firstly I\'m not talking about the some sort of crosshair aiming system anymore, I\'m refering to some sort of general timing system for attacks. In the form of a meter or some sort of reaction based mini-game or whatnot. If you\'ve played Gladius or Final Fantasy X (for the Limit Break things), you\'ll know how they use timed mini-reaction games to determine the power and succes rate of your attack.
I already told you the reason why you use it, which is \"it simply helps alleviate a bit of the monotony of combat, adds some variety, and keeps you more attentive.\" In addition it also adds a little bit of \"skill\" to the game, as opposed to sitting there just hitting stuff. Now of course it wouldn\'t necessarily have to be done so you need to be dead on to hit the enemy, but rather just the strength and effectiveness of your attack is better the more accurate you are, being perfectly accurate could have say 150% bonus. So if an enemy is really weak relative to you it wouldn\'t even be necessary to time anything.
And about the enemy stats effectint the difficulty of hitting them, that DOES make sense. In general for attacking, your aim is obviously affected by the agility stat of the enemy, that makes them more difficult to hit. Unless it\'s just automated that they will dodge or block, then no, it wouldn\'t have an effect.
Ultimately in a sense, it IS a novelty, but it is also not the crux of the combat system, merely an element of it. It could even be optional and then how well you hit would be left entirely up to chance and stats. But a number of games have used some variation of this system and it does work.