Let's assume you have a team with players good at m2m defence. We all know the advantages of the 3-2 zone and the crucial role played by SB.
I would like to use your experience to understand what level of SB should be considered acceptable to use 3-2 zone. I know this is just speculation, and there are a lot of factors we're not going to consider. There's no need to say that a team built properly for a 3-2 is a way more efficient than the one proposed in my scenario.
By the way, let's assume you have 3 guards with OD 15-16 (ID 5-6), one SF 12-12 OD-ID, and a couple of PF/C with ID 15-16 (OD 5-6).
You may play m2m defence, using the SF, or play a 3-2 zone putting all the guards in the lineup. What's the minimum level of SB do you believe the big men have to possess? For example, with SB 12, would you prefer a m2m defence or a 3-2?
I know this is just a game. Without knowing the opponent is impossible to give a proper answer, I'm just trying to understand what's the "cut-off" or the ratio (if there's one) at which you may prefer the 3-2 over the m2m without a perfectly 3-2 zone team

Thank you in advance!