score:5
The difference is that, in the pigs story, Jesus was asked to leave the region:
Then all the people of the region of the Gerasenes asked Jesus to leave them, because they were overcome with fear. So he got into the boat and left.
So the formerly demon possessed man was possibly the only witness / preacher / disciple Jesus had in the region.
In other cases, Jesus' popularity has prevented Him preaching (Mark1:44-45) and even eating (Mark 6:31)! So He often told people not to tell others about the miracles.
Upvote:3
From a strictly textual perspective, Mark is big on the Messanic Secret, whereas Luke is not.
This could simply be the emphasis of the writers - Mark (and Matthew who uses much of the same material) is writing to a Jewish audience, one that understands the power struggle and inevitable sacrifice around the "Kingship" of Jesus. In contrast, Luke's emphasis (and thereby Paul's) is on the poor and oppressed, to whom the Good News was supposed to be preached first.