I have 1 zone team (in DIII), and I've run a lot of 3-2 the last 4 or 5 seasons, usually at a -1, -2, or -3. The way I've run it, though, in games where I'd otherwise consider doing a 3-2 -4, I just run a 2-3 at -2 or so, on the theory that the other team isn't shooting 3s anyway. Haven't had a huge amount of success though.....