O3s in a greater context

In my department, communication is pretty lousy. It's a common saying among the managers that we are mushrooms - kept in the dark and fed the finest manure. We don't hear about projects or plans until they're implemented, and we have to guide our reps through new processes that we've just barely learned about ourselves. We managers had to fight to get a chance to meet as a group once a month, because it was claimed that it would detract from our assigned duties. Meetings with our direct supervisors are extremely haphazard, if not nonexistent. My supervisor has two directs - me and another person. I'd like to start using O3s with him (and my own directs of course), but I don't want to leave the other manager out of the loop or make her feel like I'm monopolizing my supervisor's time. I also don't want to overburden my supervisor by setting up a group meeting with the three of us as well as an individual O3. (Most of my issues would be covered in the group meeting anyway. I don't want to turn this into the redundancy meeting about redundant topics.) I should probably listen to the one-on-one podcasts again for more ideas, but I'm definitely interested in what everyone else has to say. Thanks, Vince