While it's true that Japan didn't have the industrial capacity to win the war, that was simply because of a lack of resources. They were short of everything, so there was no point in increasing industrial capacity, which they are more than capable of. The Japanese war leadership had to fight each other for steel.
There was no shortage of military spirit, but without equipments, there's nothing they could do. Then again, they wouldn't need to manufacture much if military hardware isn't lost. Ai-chan imagine that he would use his future knowledge to tell Yamamoto about the location of American fleets and about what to watch out for in the battles ahead.
Arguably, the reason why the Japanese navy lost was due to the old habits of 'bigger is always better' and the Nagumo's indecisiveness the Battle of Midway. If Yamamoto knows about his mistakes before the battle, he could've completely changed the outcome of the war, at least until the end of 1943.
As for the concept of 'bigger is better', that was the result of the restrictions of London Naval Treaty, which sets how many battleships Japan can have, so they tried to maximize the tonnage instead.