I don't think any o Japan's senior military leaders expected Japan to win a long drawn out war with the US.
This is the point - if you go to war with the aim of a quick win, then what if it doesn't go to plan? You need Plan B if the original plan fails, so you still come out on top, with a Plan C and D as well.
Japan's senior officers had no Plan B other than getting Germany and Italy to declare war on the US. Yamamoto was asked his opinion by Konoye, who avoided attacking the USA. Stark outlined to the Japanese ambassador in Washington exactly how he expected a war with Japan to run and explained in detail how and why Japan would lose.
No calculation was done by either Tojo or Hirohito at the fatal meeting which decided on war, as to what should be done if Japan couldn't get the Americans to the table for a negotiated peace. Relying on Germany - a country they had no real influence on - to win the war for them was a pipedream, especially as Germany wasn't liked or trusted anyway.
To me, IMHO, that ranks as criminal stupidity.