More people in New Jersey live in either the New York or Philadelphia area than the Trenton area. Newark should work for New Jersey and Wilmington should work for Delaware. Unless you restrict it to metro areas only in the state. In that case Cincinnati would probably be replaced by Cleveland.
Yes, more people in New Jersey do live in New York or Philadelphia, that is why Trenton is the biggest metro area in New Jersey. Newark is part of the New York City metropolitan area, same goes for Wilmington with Philadelphia. Cincinnati is the biggest metro area in Ohio for the fact that the city is in Ohio and surrounding cities are part of its metro area, which is the same standpoint as Philadelphia and New York City.