Even if he does fit the Annoying Family Member slot he's still a Morland, and so the very best of that bunch. In so many ways, in another book, he would be the romantic lead, going a journey of self-discovery through his courtship. There's another
NA AU over at AO3 right now that is really his story, which I've found very interesting in terms of POV.
James is kind of a spiritual sibling to Charles Musgrove from PER, who also has some blind spots and may not be quite fandom's definition of leading man. But both have good hearts, truly love their families, and their flaws are very relatable and in many ways understandable given their status as oldest sons in a large family. I like to believe that James's experience in NA molds him for the better, that he learns some hard but valuable truths about life and himself, and that his story continues somewhere in the future to a better life.
But yes, until then, James is very much bewitched, and unfortunately that's overcoming his better nature in all the wrong ways.