Positions should be as dynamic as they are strong.
A problem I have with some of the traditional BJJ is the approaches favored controlling and smothering hips which in effect:
A) Put you directly over your opponents center of power.
B) Allows for little if any mobility as you’re committed to filling space.
Don’t get me wrong, there IS a time and place for these passes while in transition directly after takedowns, but they aren’t postures in my opinion because they aren’t safe nor mobile.