I`ve always been fascinated by the hidden meaning of parables in the Bible. Even the disciples were pretty dense, needing Jesus to explain what they meant. With the discovery of the pesher technique among the Qumran Scrolls, It seems there are many attempts to disguise the true meanings of statements by inserting either a key number, word or contemporary meaning.
In a land ruled by both an overlord (Rome) and a political appointee (tetrarch Herod Antipas), and continual religious and nationalistic fervour,it seems logical that spying would be conducted on a grand scale. IOW, you watched what you spoke or got the chop. Though the Gadarene pigs` tale might seem straightforward, both the reference to 'Legion' and the number of two thousand may convey a less-than -subtle attempt to make fun of the rulers. Even the choice of an unclean animal in quantities might be another sly reference. Another oddity is that Matthew and Mark use 'sea' (KJV) while Luke uses 'lake'. If Jesus met the demon-possessed man when he landed,and the pigs ran into the 'sea', the nearest city was Gadara, approx. forty miles inland across the Yarmuk River. Long way for 'the whole city' to come to meet Jesus.
Finally, there is the oddity of two men possessed in Matthew, while only one each for Mark and Luke. Different cures?