IMO, Harbaugh is all about risk aversion. It impacts rookie playing time; and just about everything else. He was able to step outside of himself during last year's playoff run, but like a rubber band stretched to its breaking point, he eventually returned to his more comfortable state -- avoiding risks.
So his whole conservative approach impacts everything -- offense, defense, and STs. So it should come as no surprise that they'll take the same approach here -- do as little to rock the boat as possible; stay with the familiar even when it's a failed approach; tweak a few things here and there but don't change anything radically; and in a mediocre, watered down league, that should always be good enough for an 8-8 record, +/-.
You are right about Harbaugh being conservative
and being about risk aversion but in this case he's
living dangerously. He decides to keep an Oline coach who clearly doesn't fit well with the team and
now he will likely hire a guy who failed miserably as an OC with the 49ers, he's doing all of that while coming off an 8-8 season not a playoff appearance. This is going to blow up in his face
bigtime. He could get away with his comfortable approach before because of the playoff streak and
a Superbowl title, his way stopped working when Ray
and the other leaders left.