@Blood Gryphon
Have you experienced any armies being stuck in a loop in your tests? It is happening in one of my games now: An Army is stuck in a loop besieging a castle, starving, going to get food, coming back and doing it all over again. - I only noticed because it was my castle they were attacking. They have done it about 5-6 times so far.
Currently they have 800 troops but refuse to engage with my garrison (Which only has 120 troops) - It should be an easy win. I believe that they may be miscalculating the amount of food they need to complete the siege. (OR - other lords are joining the army before the siege is ready and are taking away whatever food they do have). I'm not entirely sure.
I have sent through a save game to
@mexxico so he can observe/ check what is happening. It's definitely not intended behaviour.
(This is in 1.5.8. No mods, no cheats etc.)