That does not make Natsu slower than Dragons because he can tag even Igneel in the air. That doesn't mean he doesn't have reaction timing for Lightspeed as well, that does not make any other attacks slower as well simply because, even Happy was able to dodge light beams too early in the story without Ara. Christina was never shown to have Jupiter back then, so no that does not scale. Ajeel was not wrecked by Jupiter, as like with Jacob made him unable to fight back for a moment allowing Erza to be the one to finish him off, even Erza could stop a Jupiter cannon while she was one shot and she was still wrecked by Ajeel who blocked it before with one hand, Transitive Property right there. Wendy who is not a combat type managed to destroy face while Dorma Anim required all the Dragon Slayers to combine their power. So a question for you? How can Acnologia walk around when he is in the ocean? that is a contradiction. Acno was flying so no he was not walking around, he came from the sky he could turn back into a human to do so. Not ridiculous when flying requires work as oppose to using actual magic to fly