Warband's AI "prioritized" the objective and it worked more than it did not, it wasnt 100% reliable as AI might think a better goal along the way as the circumstances changed, BUT it worked more than it did not as you could observe what AI said was lining up with their actions. It was funky but it worked and BL shouldve improved it not completely ditch it.I did observe the behavior on the campaign map, as I was dragged around to siege a random Sarranid town instead of the border settlement we were allegedly supposed to be fighting over.
Bannerlord's campaign AI is a similar utility-based AI one, apparently. And they haven't tried to dive enemy heartlands since a long time ago.
BL's AI is in a horrible state, constantly changing objectives goes into loop of "lets besiege" and "lets patrol" state, the sieging behaviors are mostly bugged as AI lifts the siege as soon as it initiates it, no sane person right now could make sense to BL's AI nor defend it behavior and call it "good".