I would suggest that they are identical, at least in performance. Mr. Jones makes no pretense of creating a better world, a new social order, for the animals. He is a capitalist. He takes care of the animals when it is to his advantage. The animals seem OK with this until the speech of the Old Major.
Napoleon, on the other hand, is one of them. He uses the idealism of the Old Major to convince the animals that there is something better for them and that he can deliver it to them. In this way, he is worse than Jones who made no pretext of improving the lot of the animals. In fact, he creates and entire class of leeches that live off the work of the rest of the animals.
Give me Jones. At least we know what we're getting.
The similarities in Napoleoen, the pig, and Mr. Jones are many. They both run the farm from a totalitarian point of view. They give the animals only the bare rations that need to stay alive. The dogs are the constant companion of both and serve them unquestionably.
The differences come in terms of gradualism. Napoleon has to gradually wipe away memories of what was promised to the animals after Old Major's speech and the revolution. Jones did not this; he never pretended to be equal to the the animals. The pigs are a little different by changing the meaning of the word equal with the oxymoron:''All animals are equal , but some are more equal than others."