It is true that things do develop at different times, as well as fall off at different times. I would say that never really count out something moving up, but at the same time never count on something staying the same...
does that make it easy for you.
The short answer is that I would say that a guy that looks like your example is probably never going to reach the full POT in that category, but that not all players will develop in the same way, ever! That is the beauty of this game, it is not computer-ish in that way. Think of things in a much more organic way!