If he was cleverer and not as believing in his leader he could have worked out what Napoleon was doing, and he could have stopped it and overthrown Napoleon and the pigs. This is an allegory of the Zealous people being able to overthrow Stalin and the royal guards if they realised communism had been corrupted. I think Orwell created sympathy for Boxer to get across to the readers how he felt about the way the Zealous people of Russia were treated by the Stalin and the guards. I think George Orwell thought Communism was good as an ideal for running a country, but that it would always struggle to work, as within egalitarian principles, leaders emerge, assuming ever-greater powers. This leads to corruption, and little better or worse that the previous system, only 'dressed differently.' He also tries to get across the sympathy for the death of Boxer, equals the Sympathy for the last chance of Communism, which is when the Zealous people were killed.