User blog comment:Hyperborean/"The House of Hades" – official expectations blog/@comment-4902593-20130510134439/@comment-3146930-20130511001231

But all of you seem to only be looking at only his physical abilities. Percy's fatal flaw prevents him from always thinking clearly and puts him at constant risk in battle. He even mentions in The Mark of Athena that he is willing to risk his life for others, but he doesn't know if he would be willing to let anyone else sacrifice themselves. This basically means that Percy will always place himself in front of a bullet, even when he doesn't need to. As a result he kind of needs to be more powerful to survive the tortures he puts himself through.

You also have to look at something else. The two strongest battlers on the team are most likely Percy and Jason (with Frank at a close third). However look at their personalities. Jason is pretty much serious all the time and because of his Camp Jupiter training, he isn't really an "Outside-the-box" thinker. Percy on the other hand is as flexible as water, constantly changing as he needs to change. This makes him much harder to counter against as his abilities are good for offense and defense.

You also have to consider how Percy and Jason view power. Jason, being a son of Jupiter, always feels that everyone is always looking up to him and that causes him a lot of stress as he constantly has to try and live up to everyone's expectations. He may even be unknowingly holding himself back so he doesn't build himself up too much. Percy on the other hand sees himself as the protector of his friends and will do anything to save them. He likes power because the more he has, the better chance he has of saving everyone. As a result, he is much more willing to push himself to the absolute edge of his abilities if it means saving others.

The seven aren't just made up of strong fighters, as that wouldn't get anything done. As much as Leo will hate me for saying this, not ever problem can be solved with a hammer. You need different people with different abilities. I mean look at the Big Three for example. Zeus isn't the oldest brother and may not be the strongest brother, but he has the ability to (for the most part) keep the Olympians in line and they respect him. Poseidon is too laid back for the job and Hades is way too vengeful.

As far as Nico's power level, I'll admit that he is strong, but he is very much a defensive fighter and most of his abilities weaken him greatly, possibly because he is still much younger then any of the other seven (except Hazel, as the two are about the same age). Yes him and Hazel may technically be about 65+ years old, but they still have the bodies of young teens. Percy couldn't even make hurricanes until he was 16 and had the Curse of Achilles.