Realistically if you were a camper, would you be Percy's friend? [All]
I mean no offense to my boy Percy, but he kinda brings misfortune to everyone he meets, sure they don't die (except for Silena) but honestly it isn't a risk I would take, I'd rather be a background character giving moral support. (Besides I think he will be closer to the 7 in terms of friends and he is basically always on a quest anyways)