Today I studied an awesome closed game of Kavalek vs Kasparov. It was annotated by Mark Diesen from chess.fm who says that in closed positions often the usual value of a piece has no meaning. What matters is the total amount of attacking pieces that you can redirect to the side of the board where the action takes place. If that amount is greater than the amount of defenders, it is often time to sacrifice. Because the defender has little space at the side at which he is attacked, he cannot find always the right defending moves. Once the king is naked, the remaining attacking pieces can cash in.
This is shown in this beautiful game here.
So maybe the idea of steerability of a game in relation to closed games is just nonsense. What is certainly nonsense is that there are less possibilities for tactics in closed positions. Maybe even the opposite, if you look at this game and Mark's comment.