i found it interesting in looking at the stats that Babin only has 4 assists in tackles. To me that shows a lack of pursuit. Maybe im wrong but when you see the other three linebackers with assists in the teens, that shows they are pursuing and making group tackles.
Review of the game tape helps in situations like this. Sometimes the stat sheet doesn't tell much of the story.
I just ran tape into the 4th quarter again with focus on Babin and it's pretty obvious why he had a low number of tackles and/or assists. Some things don't show up on stat sheets but there are a few clues in the gamebook as to his low number of tackles/assists that can be confirmed by watching the game tape. The titans ran his way twice - maybe three times. When the titans run off guard or even off-tackle right, Babin is playing outside contain and is not trying to defeat his block to the inside. If he does that, there's a risk (when C Brown is in the game at least) that he gets outside - the Cardinal Sin for the OLB.
From what I could see, Babin did fine on run support except for one play (6:58 mark of 2nd qtr) where he bit right on his key (FB Holcombe 35) and got caught up in traffic before he was able to recover contain left. If he would have recognized the misdirection and stayed home, he could have had a tackle for a loss. Simmons and Coleman came up and made the play which was a 3 yd gain by C Brown. Even into the 4th quarter, it appears that Babin did a good job on contain on off-tackle right. That's most likely his primary assignment.
His biggest challenge appears to be defeating blockers in pass rush situations. He needs to shed better. He did a good job hurrying McNair twice with strong outside rushes (beating Miller around the edge when there was no TE or FB) and once on an inside stunt at around the 7:00 mark in the 3rd but in many cases (in the first half especially) he was getting double teamed and stopped in his tracks. I saw one case where he couldn't beat Miller one-on-one with a series of moves as McNair moved around in the pocket. As the game went on, I saw Babin apply good pressure even though he didn't get his hands on McN. Peek came in for Babin a few times late in the 3rd and early 4th. He did nothing good - nothing bad. He seemed to have trouble with Miller one-on-one as well.
One of Babin's assists came on a play where he was lined up against Berlin in the slot receiver but he recognized run and came up to help stop Antowain.
All in all I think Babin held his own - at least into the 4th quarter. He didn't make any mistakes but he didn't make any big plays either. He's only played the position for 6 games in his life. I think he's still focusing on fundamentals now and his assignment, i.e., the playbook is running through his head when he comes up to the line. As he gets more experience, he will rely more on instincts than thinking about what he's supposed to do. Now if Peek only had a playbook ...