Oh, I didn't know what X did and made assumptions.
If you split file permissions into two halves - defining the initial permissions / modifying something that already exists - I can see how it makes sense to do both with the same syntax since modifying existing permissions is worse with octal.
If you split file permissions into two halves - defining the initial permissions / modifying something that already exists - I can see how it makes sense to do both with the same syntax since modifying existing permissions is worse with octal.