How to grade up to 4c?

Grades are supposed to reflect how hard it is to redpoint a route with the best optimal beta. At the same time, the grades should assist a beginner who is searching for a 4a to warm up on, irrelevant of how hard it is to redpoint. Further more, if we are talking kids or people who are trying out climbing for the first time, also length, reach and potential pendulum swing etc have impact on the perceived difficulty/grade. In other words, a 25 meter route climbing a bit diagonal on reachy granite will never be perceived as grade two even if an expert never need to use their hands. On the other hand, a seven meter straight up where you always need your hands to pull, could be graded two. Nevertheless, in practice, the grading for both the 8a as well as the 4a, are done based on the same idea. The success rate and time invested for the community! The only difference is that, the lower you go down in grades, the more the grade should reflect the onsight and flash difficulty.