Snowball and Napoleon argue almost every issue that arises. What is the only thing they agree on?

Anything they agree on happens in the early chapters. I would consider,

1. Making the farm house into a museum

2. Snowball and Napoleon also re-name the farm Manor House.

They also agree that the cows milk and extra apples should be added to the pigs mash. This significant as this is the first corruption of the spirit of animalism. Once the ruling class accepts this, the spirit of the revolution is lost. It is only a matter of time before totalitarianism rules again.