Iowa has a strong position, with the Papacy and the Republic of Bluffwoods to the south, the kingdom of Platte and the duchy of Kansas to the east, on the other side of the river, to the north the strong kingdom of Lakotah and the tribe of Freeborn, while to the north east there are rust cultist tribes and to the east the Republic of the Quad Cities and the duchy of Forgottonia is on the other side of the river. The presence of a major river allows the arrival of reinforcements even from far away lands, making it an easy crusade target should the rise of the consumerism happen there. The kingdom has a compact form, making it a difficult target for a raider. Also the domain of house Greysnow is on the southern border, making it way safer.
The strong defensive position, and the ability to field 5k men at the start make Iowa a true stronghold of Catholicism, and the presence of nearby Catholic rulers and even the Pope make Iowa a poor target for holy wars as well.
AI Iowa is very defensive and, more importantly, won't waste its energies in useless wars against its catholic neighbours, thus the region is stable and able to stand against threats like Lakotah. Interesting is the relation with Platte. It's not rare that the two kingdoms will form a deadly alliance, usually this means the downfall of Lakotah, or at least the fact that between the Pope and the other religions there are 10k men defending him.