Not necessarily true. Remember that corsi is strictly counting shots for and shots against. It actually has nothing to do with puck control directly. It is a statistical assumption that the team taking more shots has the puck more.
As for how this applies here? The same as it applies to my team. My team isn't near as talented as yours or the many others that sit at the top of the standings. Yet I have good corsi numbers too. That team is another example, just like mine is, of getting the right players that they need for their system but with two flaws sinking that team. Lack of goaltending and lack of scoring. They have a talented enough team to fight for a playoff spot if they had a good goalie. I have yet to look at the games that team has played so I can't say if they are true puck possession monsters but they have a good enough group talent wise that they can be a solid puck possession team.