Well, that's true I guess, but if you go like this: Charizard -> Bisharp -> Blissey, then Blissey is crippled by Knock Off the next turn, and the Sun won't be up unless you've Mega Evolved, which isn't always the case, so the Sun isn't always 100%, and there's the fact that Fire Blast could miss. All your points are very valid, but I still think it should stay where it is.