These positions seem to parallel each other, because they are both based on retribution of the past. To be fair though, "the past" is more recent for the Stormcloaks than it is for the Paarthy killers but you can't deny the similarity. Most legion supporters are aware of the negativity and wrong doing caused by the Empire. Paarthy supporters know what happened 1000s of years ago (and the meaning of his name). Ironically, a lot of stormcloak supporters spare paarthurnaax and vice versa for many legion supporters. Just an observation.