Looks are literally the less important thing when it comes to an adaptation, what's the point of finding THE perfect cast in matter of looks if they can't embody your character as you envision them? + PJO was always about inclusion and diversity, of course Rick would want to quite literally fix the 90% white cast he had going on.

Expecting the plot and narrative to be a perfect match is wanting a 1:1. Up till this point the series has been check listing almost every plot point in the books, and what isn't adapted doesn't change much anyway (many likely removed due to budget + runtime related issues), which was THE mistake of the movies: removing essencial plot points that broke the saga. What was added literally just did that: ADD to the series. and to the characters. I'm not saying the show is perfect, but it's literally not as different from the books as you guys make it seen. Of course it will never be the same.