So what can we conclude from all this, it took Naruto approx 51 days (8+39+4) to complete the wind rasengan when it could have taken up to 7 years (2.4+3+1.6). Lol, 7 years that’s your high school education right there. The wind rasengan could have been useful on the last day of school. Also I just thought I'd point out Orochimaru's plan to learn all jutsu by extending his life using the soul transfer jutsu, Naruto may compete with this too. So far when Naruto has used the shadow clone training he has been using his normal chakra which is 4 times larger than Kakashi's and if he uses the nine tail's chakra as well he would have 100 times kakashi's chakra. This now means Naruto with the nine tail's chakra is 25 times(100/4) bigger than his normal chakra and therefore able to create 25 times more shadow clone and as a result the shadow clone training will be 25 times faster. For example, Naruto took approx 8.125 days to complete his wind nature training with his normal chakra, now with the nine tail's chakra it would have taken approx 7.8 hours( 8.125*24 / 25). AND if Naruto then enters Sage mode WHO KNOWS how fast Naruto will learn Jutsu in the future. This will be very useful BEFORE and DURING the upcoming war.
I also found a neat comparison to Dragonball Z, in that manga they had the Hyperbolic time chamber where you can train 6 hours for every minute that passes in the real world. So for Naruto to compete with this he would have to train with 360 clones ((6*60)/1). Naruto is actually almost there, he can use up to 200 clones when high chakra control training is needed
This thread may start making you think Naruto can do anything which is wrong. I just wanted to bring up the concept of chakra affinity. Having an affinity to a element allows you to use the strong jutsu's in that element's field. All shinobi can use jutsu from all elements but they are weaker if they don't have an affinity towards that element. Kakashi's analysis during the Kakuzu fight explains this well, based from all the shinobi we have seen so far you can have up to 3 affinities (fifth muzikage). Nagato is the exception, the rinnegan gives affinities to ALL elements. Shadow clones won't help Naruto in gaining affinities as this all to with your blood(genetics). So far Naruto has wind and water is speculated amongst fans, but it wouldn't surprise me if he just had an affinity to wind given the OUTRAGEOUS potential Naruto has with shadow clones.
I'm very excited about Naruto's next training arc as I believe hes gonna rewrite the textbook when it comes to training. Madara better watch out lol, I honestly believe Naruto has the potential to be the greatest of all time.
Hope you enjoyed the read.