Here’s the thing about the zone, IMO, it’s hard to be wrong with your setting in the favorable direction.
The 3-2 is really good about lowering 3FG%. It’s very rare that I’ve played a heavy - setting and some team shot over it. One player , maybe, but a team almost never. I usually err on the side of - with the 3-2.
I play less 2-3 but in a similar case, teams don’t pound the rock inside on me when I play heavy +s.
The rubric, In my case, gives me a backbone to make decisions. In all honesty, I am always look for away to make the - a bigger absolute value to help with rebounding. I think the biggest mistake people make with zone is playing to high a setting. I look at a teams that play me and am just befuddled why the other coach didn’t go -4 or -5.