yah it said he split his chakra evenly between the clones so neji couldnt tell which was the real naruto by looking at chakra flow/reserve

which neji can do with his byukagun (spelling)

making a kage boushin wouldnt multiply available strength, u have to spread it out

edit: by strength i mean chakra and without kyuubis chakra added to the clones made.. well theyd be narutos... and narutos wouldnt be able to hurt neji