If they can't clear the hurdle they should be given C-, D grades and placed on performance review process.

If they meet all expectations of the job of a regular classroom teacher, they should be promoted out of such a junior grade in a shorter time.

Yet there are many GEO3s who have been stuck at the grade for 8 or more years without ever being on PRP or getting a C- and below. Why? Does every GEO3 need to hold internal KP appointments before they can even smell a reasonable promotion interval? This is what I mean by shifted goalposts. Internal appointments are evolving to become the 'norm' to help good young officers avoid stagnation and hopefully retain them rather than losing them to other more promising careers.