I have also used a fair bit of patient but can't ever recall seeing a 2/3 zone used against me. Obviously we all agree 3/2 is the best defence but my (untested) thinking is that comparing the options:M2MOpponents SG playing at C taking outside shots against your C with atrocious OD.2/3 ZoneOpponents SG playing at C taking outside shots against your PG and SG who are "working their asses off" to cover the outside and performing much worse than their normal wondrous levels. Maybe down to around as low as prolific to respectable effectiveness.