How do Old Major and Napoleon's behaviors impact the animals? (compare and contrast)

This is a great question. 

In the beginning of the book, we read of Old Major.  He has a dream and calls the animals for a meeting, where he urges the animals for a rebellion against man.  He is a cogent speaker.  He says that man is the only animal that only consumes without producing.  He also says that the animals only work, and in the end they are slaughtered.  In short, they are slaves. Old Major seems sincere.  The reader does not know this for sure, because he dies in chapter two. 

When it comes to Napoleon, he lives long enough for the reader to see his character.  He is a tyrant and conducts the farm to please himself and the other pigs.  Therefore, he is not sincere about the revolution. In fact, the farm is far worse under his leadership, and at the end of the book, he turns into a man. This shows that he is a new Jones.