well, its not just that. I remember reading an article about the first movie, where del Toro and Villeneuve changed a lot in a certain scene to make Alejandro a more mysterious person (I believe it was a scene where he would explain his history to Emily Blunt's character); basically cutting down on most of the lines. That's something that happens during filming, when a director and the actors look at a scene and are open, able and willing to change it up a bit to make it a bit more interesting. This is also dependent on time and budget available, and the amount of 'power' the director has to change things up. It could just very well be that for Soldado, they just filmed the script "as is", which gave us a decent but kinda silly (compared to the first one) end result.
