Even though Carlo can skate out the puck with poise at times while both he and McNabb can make simple-to-medium difficulty passes, neither of them specialize in moving the puck, carrying it out or finding ways to beat a heavy forecheck. They're both fine.
My post that they would be caved for being unable to move the puck out wasn't entirely serious, but it does point towards the NHL-wide move towards always having at least one blueliner on at any given time who is good at transitions. Again, those two are just fine.