The somewhat lighter precision of an intrinsically hasan transmitter leaves a modest residual risk of an error. When sufficiently independent and reliable routes agree on the same report, accidental error becomes less likely and the probability of accurate preservation increases.
«لِلصُّورَةِ الْمَجْمُوعَةِ قُوَّةٌ»
The evidence considered together possesses a strength absent from an isolated route.
This is not a mere counting exercise. Several pupils may all copy one mistaken source, giving more repetitions of a single error rather than independent confirmation. That is why the distinct sources and actual independence of supporting chains matter.