@psych96 ... I'm so sorry you're going through all this.
Since you've lost confidence (and I don't blame you at all) in your original surgeon and their practice, going back to see them would seem to be pointless. I think you're better off with fresh eyes on your knee - someone who does not have a preconceived opinion.
I'm not surprised that your TKR knee is a bit smaller than your other knee. You've been wearing a brace and, while it may help with pain and mobility, it does restrict muscles from movement they need to keep strong. They can atrophy, but muscle tone can be regained once you're through all this. When you use a brace, your leg can become somewhat dependent upon it, which it sounds like you are noticing also. This also will be temporary once you can start exercising your leg again. In the meantime, can you do some exercises like ride a stationary bike each day for a while? That will at least put your muscles on notice that they are not going to be allowed to take a free ride forever and they need to continue to work properly.
Be careful when searching for stats on the internet regarding revision specialists. These are the doctors that see the problem and difficult cases day after day. It is logical that they might have a slightly different complication rate than surgeons doing straightforward primary cases. When I checked
Dr. Lee in Pro Publica, his complication rate was 2% and he ranked on the lower end of "medium" on the chart. These numbers are just for Medicare patients, but they can give you an idea of a specific surgeon. You might want to at least talk with him or the surgeon in Philadelphia if you're willing to travel there.
I think you do need to have some additional consultations until you find a doctor that you are comfortable with.