Board Thread:Fourth Databook/@comment-24577388-20141105025614/@comment-2120712-20141105062013

Maybe while they have learned to create said chakra nature, their skill with it maybe rudimentary at best. Like with Ei(fourth raikage), while he has learned to create water release chakra, he has basically focused on one of his elemental natures above the rest(lightning). Being able to create a nature is one thing, be able to use it for high level ninjutsu and genjutsu is another which is why Kakashi is shocked since most none kkg ninja probably focus on taking one or two elements to a high mastery. Though considering Kakuzu age, he has had plenty of time to delve into elemental nature training.