You can argue that only the victorious protagonists are the ones that matter to the plot of the story and the metaphor Orwell was trying to make about the communist movement. That he believes that the communist movement was of all lies and that victory only mattered to them, and that similarly only victory mattered for Napoleon not the fact that he lied to everyone. We can go deeper by saying that Orwell is trying to comment that the statement in the question was the central philosophy for communism. You can link Stalin with Napoleon, through this.
Overall I would have as my general thesis, have 'In order to suceed, the truth does not matter, as it is the truth that is the barrier to success. This is what Orwell is saying etc. etc. '
Saying that the truth does matter and not victory, is the more 'happy-joy' way of looking at it, that it is morally correct to view it this way. We can then go further to contrast whether morals matter or not in politics. And how Orwell is saying that even under capitalism (Mr Jones), morals matter as much as under Napoleon (communism). Its a very broad question, but as long as you stick to the question you should be fine