A generalist accountant isn't cutting corners. They simply don't see enough dental clients to build genuine expertise in how the sector works. They won't know, off the top of their head, how NHS superannuation interacts with your pension annual allowance, or what HMRC's view is on associate expense claims.
A dental specialist does, because those questions are the everyday work rather than the exception. That is what lets a problem be spotted before it becomes one, and it grounds the advice in how NHS contracts and associate agreements behave in practice, not just in what the textbook says.