Hard to give good advice I guess without seeing your operation. This is just an opinion but to me it looks like he still isn't getting enough to eat. That hollow triangle between the last rib and hip should be full if the rumen is full. Not sure if you could post a pic of the pasture he is grazing or what exactly he has access to eat. Glad you didn't just run off. Probably forgot if you already said what the goals of your operation are. The genetics will play a role in how easily the cattle will gain weight and marble so if your wanting to butcher the calves keep that in mind. Really odd "sales pitch" from the vet. Something still seems really wrong. If you have time start doing a lot of research on your own. Reading, YouTube videos, etc… maybe find some successful operators in your area to bounce ideas off of and get advice from. Some people in this industry will give you a hard time or take advantage of you but there are also a lot of really good people out there if you can find them.