So now you have me thinking even more. With a 3-2 would you not have a decrease iń rebounds?
I sorta of get what you are saying about offensive. But I don't think it's a good policy to run an offense that is your weakest. Outside is definetly weak for me.
2-3 Zone: Increased inside defense and rebounding at the expense of a lot of perimeter defense. Somewhat slow pace. (From Rules) It is generally regarded as the best defense to use against an inside offense but will be a huge problem should your opponent decide to use an outside based offense.
Best Against: Look Inside, Low Post
Worst Against: Run and Gun, Motion
3-2 Zone: Gives an increase in perimeter defense at the expense of interior defense. Slow Pace. (From Rules)
Best Against: Run and Gun, Motion
Worst Against: Look Inside, Low Post
Also would PTB give me more quality shots then R&G against a 2-3 zone?
3-2 doesn't have a decrease in rebounds necessarily, no. It doesn't get a boost as 2-3 does, and if you have a good rebounding SF the result may be a net decrease since you pull him away from the basket, but there's no established penalty for RB specifically from 3-2.
The easiest way to think about your offensive dilemma: do you have better outside shooting than bots? Because he gave up 33% from behind the arc in his Cup game to a bot team. He's given up a high percentage from outside every game this season. There's a reason for this: he's putting up extremely low OD ratings and (for IV) extremely high ID ratings. You don't need to have lights out shooters to abuse a 2-3 defense, especially one that's all big men.
While doing something your team isn't ideally constructed for isn't always the optimal play, you have to remember that this is a game of matchups and your opponent matters. If you have an opponent that packs the paint with big men, all you need to do is have your guys pop midrange jumpers all night long. There's no point in trying to chisel through a wall with a rusty spoon when it's so easy to go over it!
Personally, I'd aim for one of the slower offenses too. When you're going against a team that can't defend you from outside but will have a huge edge on the boards, it's much better to take longer to get a high quality shot and reduce the chances that you miss and almost certainly concede a rebound. I think that as much as the midrange focus would be a reason to strongly consider Motion over R&G or PTB.
The best thing I can do for you is this: using the advanced stats from the USA Offsite (I think you're a member), you can see that your opponent is giving up 18% shooting on contested inside shots, 27% on drives, 27% on jumpers and 37% on threes. Yes, you read that right, the highest shooting percentage he gives up is from beyond the arc - and that's without the bonus to outside shooting that comes from playing an outside based offense. If you want to put on a helmet and send your guys to run into his interior wall, or try to build a wall yourself with overmatched players on defense, feel free, but the smart play here is to go over his wall and to make sure he can't get past your perimeter when he has the ball. Motion and either 3-2 or M2M is definitely the way to go.