I think it depends on whether they're good at outside shooting or not. If they are, then 3:2 zone is probably necessary to close down their shooters (or maybe even FCP to break up their play), but if their shooting percentage is not so great, why not let them shoot from outside and go 2:3 zone to boost your rebounding. If you're good on inside defence, why let the other team drag you out to play on the perimiter if you can rely on them missing lots of shots anyway? As long as you claim the rebounds then that's good too.