He's got a ewe neck, but it's not from lack of proper collection under saddle. It's conformational. That may make his neck appear to jut out and perhaps lead to the illusion that it's too long, but I disagree that the length is a real issue here. He's not a nice, clean throatlatch, unlike many ewe-necked horses, which thins the neck and again lead to its appearance of excess length.
Besides the neck, the biggest thing I would fault this horse on is his rump. He has an excessively steep croup that leads into straight stifles and gaskins and slightly posty hocks. While this allows him to collect and drive from behind fairly well, he'd never be a highly competitive athlete.