Hi Amy... sorry you had to go through that. I would trust the person who has the most knowledge on the subject.
In your case, given that he did the surgery and has seen many recoveries, that would be Dr. Gross. I understand your concern, but it really comes down to who has the most experience in that specific area, and what sounds correct to you.
I haven't had any of these situations since the surgery, but had them before. My primary care doctor went through a long list of possibilities and tests before I finally decided to see my first surgeon. I went through tests for Lyme disease, neurological problems - that one was fun, needles inserted in my arms, legs and thorax and sharp electric pulses run through me, long runs of physical therapy. Then when I went to several surgeons, they all spotted the OA and except for the last touted THR instead of HR.
So my point is that there is often disagreement, not because they may not be good doctors, but because they either don't have enough information, because it is not their field of expertise or because they have reached some philosophical conclusion that they can't retreat from. In the end, I tend to trust the ones most expert, but also use my own goals and gut feel to choose among the experts. In your case, you have a greatly experienced surgeon who knows exactly what your hips should look like, I would go with him.