Wow how naive are u that u think missiles are simple, I think you need to go outside and get some air or maybe take a break from anime a bit. Eventually chakra will run out and sense it seems that the ninjas cant use many jutsus without using up a lot of chakra. Also eventually the ninjas will get tired, it does not take a lot strength to pull a trigger and when I said far away I meant the ability to launch the missile from a long distance.