But nobles trying to destroy the controlling regime should not arrest allied nobles helping them and ship them off to an enemy dungeon.
I'm fine with them not reducing the chance. But the presence of allied troops should not increase the chance of capture.
Try arguing that with a bunch of illiterate peasants trying to abide by noble law that they don't really
get. They can be summarily executed basically at any time, for strange and archaic reasons or none at all, so in their desperation to do the right thing they sometimes cock it up.