What does "you'd think ..." mean here? And if the song were not enough, the shattered castles of the Reynes and Tarbecks still stood as mute testimony to the fate that awaited those who chose to scorn the power of Casterly Rock. “The Crag is not so far from Tarbeck Hall and Castamere,” Tyrion pointed out. “_You’d think the Westerlings might have ridden past and seen the lesson there_.” “Mayhaps they have,” Lord Tywin said. “They are well aware of Castamere, I promise you.” (Game of Thrones) The context: Once the lord of Tarbeck Hall and lord of Castamere had rebelled against their liege lord Tywin, lord of Casterly Rock, and Tywin destroyed their forces and castles mercilessly. Now Tywin's bannermen the Westerlings of The Crag also betrayed lord Tywin. However, this time Tywin didn't seemed to have been enraged as much as his son Tyrion would have expected. Now I have some questions about the underlined part. I wonder if the expression "You’d think" express the idea of "contrary to your expectations" here? Thank you.And are "might have ridden past and seen" and "might ride past and see" interchangeable here?