ex·cep·tion·al
ˌikˈsepSH(ə)n(ə)l/
unusually good; outstanding.
"a pepper offering exceptional flavor and juiciness"
synonyms: outstanding, extraordinary, remarkable, special, excellent, phenomenal, prodigious; unequaled, unparalleled, unique, unsurpassed, peerless, matchless, nonpareil, first-rate, first-class; informalA1, top-notch
"her exceptional ability"
Actually it is, if your a medic (forgot about that) and you have exceptional chakra control you can do it. Shadow clone is a kinjutsu but it was done by an academy dropout. Having exceptional chakra control is having control over your chakra (which is in your body). I didn't say good or above average people can do it though.