I have no idea where to begin....I have absolutely no clue what you are talking about with those calcs lol. Anyway, these are two completely different pokemon who fill completely different niches, Chansey being a special (and often physical) wall and P2 being an offensive tank as well as a utility counter to many common threats. Don't just try to distinguish a pokemon from another by running an inferior set, as you apperently are going to do. If you think the other poke works better, then use it. You are gimping yourself otherwise.