Who does all of the farming in Cradle? In a society so focused on martial martial abilities. Who would waste time on farming? We know the population of Cradle is many times greater then Earth. So tens of billion of people need to eat. The only real solution I could think of is if there are Paths that happen to both greatly help agriculture and has combat potential. Or as we saw in book two slavery.
There are Paths that are used for agriculture and irrigation, they're just usually low-key. There's a (very) brief reference in Blackflame to the Redflower family, who are in charge of feeding the Empire. By law, they are neutral in every conflict, and anybody who starts a fight with them or tries to pressure them will soon regret it.