One thing I'm not liking is how in universe time has moved so fast its been what 18 years shins in his 30s and there has been no advancement in the plan how is this stuff supposed to be accomplished within there lifetime let alone ten years since the 15 year time limit has been chugging along with multiple losses
There is a ton of subtle advancements. You cannot just topple other countries so easily. First of all almost half of the time our king was not even an adult and didn't have full power.
Also, this is not the "universe" time, this is based on actual history
Of course a lot of things is added and made up, but important years remain. You can check years and learn more about the actual history, but it will kinda spoil everything to you, even if this battle will be a possible win or not.
Now both Sei and Shin are in position of great power and can greatly affect things and there is no big problem remaining, now they just actually need to defeat the other countries (and one of them already basically surrendered, remember)
The raws r like 20 chapters ahead this is gonna be a long one also sucks these credit card companies making shit difficult to buy from the Japanese websites