Board Thread:Naruto Discussions/@comment-30168130-20170420215833/@comment-3568954-20170504115335

from the moment naruto first used multi shadow clone jutsu he was doing so under his own chakra, we saw no red chakra surrounding him. him using the shadow clone jutsu with his own chakra weakened the seal, and naruto has always been able to create hundreds of shadow clones with his own chakra.

by the time of the war naruto's chakra was massive, way more than 4 times that of kakashi's when naruto shared his chakra with the allience hashirama stated"you shared this much chakra with everyone?, its almost as much as my chakra, No, there is kyubi chakra here as well" hashirama was stating that naruto, minato and kurama's combined chakra was almost as much as his own in volume, but with the wording it implies that most of that chakra given was Naruto's by the time of sasuke and naruto's final fight hagoromo had awakened indra and asura's full power in naruto and sasuke meaning by then naruto's own chakra surpassed kurama's in volume

also it was stated early on that when you first learn a technique it might take a large amount of chakra to use said technique but over time the amount of chakra required lowers because you get more efficient at using said technique. so it can be assumed that by the time of the war naruto doesn't require even a fraction of a fraction of a fraction of a % of his total power to create hundreds of shadow clones

its the same reason why madara can create a fire release technique that can span such a massive range even though he doesn't have a super amount of chakra compared to say Hashirama. its the same reason Genin like Obito can use fire release better than jonin because of the uchiha's history with using fire release