Well, he spent six years specifically at camp Jupiter, with its own, very different way of splitting up the groups, into cohorts instead of which god was your parent. He was also high in command of the cohort, I can't remember what my final decision was to what rank, but it wasn't the highest possible, I know that much. If camp half blood and camp Jupiter are one camp, then the set up of camp Jupiter and the camp in general wouldn't have existed.