This is true. While on the whole, as
@skribs says, it's easier to recognize the difference between ranks at the start of each rank, there are also people who simply don't rank up. I hung out at ranks a long time, so was often more developed in some ways than the folks in the rank above me. One of my training partners never went for BB because he didn't care to teach (required for BB), and he was probably more skilled than any of our BB in most ways - certainly better at the base principles than I was.