Naruto might be lacking in strategy or maturity, but he definitely is not lacking in leadership and i think thats a big part of becoming a chuunin, i mean if naruto has leadership and power i think it would be best if he was a chuunin from here on out and learned to be more mature as a chuunin, he wouldnt develop staying as a genin
anyways, i know chuunins have to be all serious and mature, but its not like they are on missions that are dangerous all the freakin time, look at Iruka, hes a school teacher most of the time