The more I think about it, I really like the arcs presented to the main characters in this one. In the first movie, Matt & Alejandro are who they are. Kate is the wide eyed agent who is exposed to the horror and reality of the situation, but Matt & Alejandro stay the same as it's almost just another day for them.
In this one, Sheridan decides to flip all the main characters as the film goes on. Alejandro has the lynch pin that could get him potentially to Reyes for a brutal revenge, but his compassion for the situation and Isabel eventually flips his mindset this time and he in turn would rather risk capture or death to try and give the girl a chance.
Matt tries to stay true to the "dont' give a ****, just tell me where to be and what to do" all the way up to the point that he's now told he must kill the girl and Alejandro to 'clean up' the mess they made in Mexico. In the end, he flips and disobeys orders by bringing Isabel home.
We meet Isabel as the well-understood daughter of a cartel boss beating the **** out of a classmate at a very private school in Mexico City. She's so aware of who she is that she even wields power over the head of the school like a boss. However, when she's thrown into the world her dad operates in, she's mortified, and then ultimately becomes disassociated completely.
We meet Miguel looking like the compassionate older brother ensuring his little siblings get to school in what is clearly a poverish area of McAllen. He's then picked up by his cousin and eased into the idea of making money as a human smuggler across the border. He's hesitant at first, still clean cut...then he gets a taste of the money, and ultimately is the guy who shoots Alejandro after another young boy couldn't. It made him uncomfortable, and then we meet him a year later tatted up, fully into his new role with whatever respect comes with it, but the show ends as he walks into who knows what seeing the dead come back to life in Alejandro.
I really loved how well they did that with each character. What I hope going forward is that they don't have it set up to where Alejandro is training Miguel to be some assassin like him or anything. Because the way it ended, there's enough loose ends that they don't have to continue that storyline. We don't know what Matt's standing is with the gov't for breaking the order (assume they're still having him do their dirty work though). We don't know if Alejandro is in good standing with the US since he wasn't taken out.
We don't know if Isabel would be the connection to the 3rd film or if she's standalone for this movie.
I'd love something that ties it back together, but somehow Kate during all this time has worked the straight and narrow up through the ranks, so that in the 3rd, she's actually got a power position over Matt/Alejandro. Play the storyline out however, but make the climax be that she is keeping them contained as much as she can until it gets to a point of no return and she has make the call to let them "get dirty" but knowing that she is doing it because she knows that they'll get it done, and whatever feeling that comes with her ultimately accepting that this time it was her decision to have em do it.