Thank you for your very good question! 🙂
The way to understand this, is simply by observing how night time changes into daylight. You will observe that change is never “uniform,” but change is happening nevertheless. In the Golden age we have “status” which is nothing else but the expression of being “numberwise.” Is the “16 kalas” (celestial degrees) of Narayan equal to the 16 kalas of a “cremator”? Obviously not.
Equality is a mirage. The term “16 celestial degrees complete” means completeness as far as being “full in your own capacity.” Your capacity is different than anyone else’s.
Brahma Baba explained this concept of “gradual degradation” (entropy) using the metaphor of a full moon (16 celestial degrees) and how it degrades to a lesser extension (quarter, new moon, etc.) In his example, He has chosen to arbitrarily use “14 degrees” for the full “silver age,” when now we can see that this is not so; for things degrade in the Silver age as well. See?
Therefore, those “kalas” are merely a way to explain gradual degradation in time.