>>44671367The difference isn't actually all that arbitrary. Physical simply means "powered by pure physical muscle force", while Special means "powered by otherwise supernatural - i.e. special - means". Physical and special as categories mostly aren't concerned with how damage is dealt, but rather how the attack itself is powered.
A Pokemon using Razor Leaf is using its strength to throw leaves fast enough to hurt you. A Pokemon using Magical Leaf is literally using magic to propel leaves and the damage might not even be a result of the physical force behind the leaves. Same goes for Rock type attacks, even if they're not portrayed that way in the anime. Rock Throw is just that, throwing rocks. Ancient Power also throws rocks at something, but they're being thrown by supernatural geokinesis and not brawn.