Why do we need a madhab?

[hanibal]

@cricketplaya

Walaykum as-salam,

Bro, if we established that all 4 schools of thought are from the sunnah then how would we see them as fractions of Islam? The sahaba had differences of opinion amongst themselves, were they creating fractions?

Can you name a single school of thought based on the difference of opinion Sahaba (RZA) had?