In the book Animal Farm, Napoleon get's influenced and always puts himself first. He is overpowering and demanding, and greedy for power and corrupt. He tries to consolidate his power. He manipulates to get what he wants. He praises himself for all the things he's done for the animals.
Snowball is zealed about rebelling. He gives great speeches. He is more of a vivacious pig than Napoleon. He is friendly and lively. He also brings literacy to the farm. He also devotes himself to bettering the animals in intellectual ways. Napoleon believes in the happiness of his citizens. At this point it's obvious to why Napoleon or Snowball would be a better leader for Animal Farm.
Napoleon wanted to be the leader but Snowball was more favored. This is why Napoleon chased him out with the dogs. Both are corrupt but Snowball is a lessor evil.
After seizing power political power in France, Napoleon crowned himself emperor in 1804. Snowball leads the animals to victory in the battle of Cowshed. This is how both gained power.
