Please tell me why the Marjas have different opinions on verdict or fatwa and if they differ…so on wht kind of ahkam they differ plz explain….coz all of aalime deen become marjaa by reading same 4 books

They differ due to number depending on their understanding of the traditions as well as the traditions available to them. They normally differ on Ahkam in relation to it being musthabb, makrooh and the Likes. They don’t differ in what is Wajib or haram