«وَتَتَفَاوَتُ رُتَبُهُ أَيْ الصَّحِيحِ، بِسَبَبِ تَفَاوُتِ هَذِهِ الْأَوْصَافِ الْمُقْتَضِيَةِ لِلتَّصْحِيحِ فِي الْقُوَّةِ»
The grades of authentic reports differ because the qualities supporting authenticity vary in strength.
Two chains may satisfy all five conditions, yet their transmitters need not be equal in precision, uprightness, or other features that strengthen a chain. Both can remain sahih while one is stronger than the other.
Example: One chain consists of outstanding, exceptionally consistent preservers; another is also authentic but contains reliable narrators of somewhat lesser distinction. Both may be accepted, but the first can carry greater evidentiary weight. This is ranking within sahih, not the simple contrast between authentic and weak reports.