Imām Ahmad (RA) was once discussing an issue and some people quoted certain Ahadith to refute him.
The Imam became angry and said:
صبيان نحن؟! ليس نعرف هذِه الأحاديث؟!
"Do you think that we are some kids from the streets who are unaware of these Ahādīth you're quoting?!"

Dedicated to those who underestimate the fuqaha and keep saying: 'this Hadith did not reach them!'
These Ahādīth did not fall from the sky in the 21st century you did not discover something new.
They were known and discussed at great length before you were even born.

The disagreements of the fuqahā are not because they are unaware of the evidence, it is usually because the evidence can be understood differently, or they may consider them abrogated due to other Ahadith, etc....

...And these Madhāhib are not based on the words of the 4 imāms alone they have been fine-tuned for 1000+ years, by millions of scholars.

["As-Sunnah", of Khallal, 2/359 -  إسناده صحيح].