Changing the culture and actually teaching defense, going back the fundamentals and forming a foundation to build on can definitely help us on that end of the floor and we'd likely see a decent bump in games won if everyone buys in and if Malone is anywhere near as good as we hope he will be. Just by having structure, knowing your opponent, being on the same page with screens/switches/cutters/flares/rotations/etc, we should see noticeable improvement. It will take some time but as long as we lay a foundation and build one step at a time we'll see the difference.
However, culture change or not, Malone being a defensive wizard or not, we've put a ceiling on the level we can reach defensively with our off season moves. At a certain point it comes down to the defensive capabilities of the players on the floor, and it's not tough to assume we'll have more mismatches going in the opponents favor than ours unless we actually see more roster movement. Vasquez and either MLM/Thornton will be a mismatch favoring the opponent, and with what appears will be a Vasquez/MT backcourt to start the season we'll have an uphill battle every night. We still don't have a starting SF. Maybe Mbah will start and can have success defensively as a starting SF, but I'm not convinced he is a starting level SF in this league. I'll give him the benefit of the doubt in this discussion though. Then looking at our 4's, whether it's PP or Landry starting that's another mismatch in favor the opponent. Cuz while I believe he can improve a considerable amount defensively is still below average and will struggle even more on that end until he gets a real defensive presence next to him, which PP and Landry aren't. Maybe JT starts at the 4 but I doubt it given we currently don't have a backup center and he's the only guy we have who can play there, and given PDA couldn't resist giving Landry a 4 yr deal I'd assume he likes stretch 4's and will prefer a PP/Landry PF rotation.
Of course the roster can change but as of now one can easily make the argument 4 of our 5 starters are below average defensively with the benefit of the doubt going to Mbah who might not even be a starter. We've heard a fair amount of talk about defense, but simply put our roster moves don't back that strategy thus far, it's actually the opposite where our backcourt defensively is worse than last year and our frontcourt is worse as well, as to this point we've seen Aldrich walk and the only big we've brought in is Landry, and in the backcourt we've seen Reke/Douglas leave and brought Vasquez and a rook in, a rook with above average defensive potential no doubt, but it's still an overall loss defensively to this point and I'd argue significant at that.
Even top defensive coaches like Doc and Thibs need top individual defenders to have success on that end. This talk of team defense and Malone bringing structure, while a positive only means so much if our FO isn't giving him the pieces to succeed on that end. It would mean a helluva lot more if the moves of our FO were in alignment with the apparent defensive philosophy.
Edit to add: There have been some very good teams when it comes to well coaches team defense and knowing and sticking to a plan, but most teams who excel when it comes to team defense defend on the philosophy of funneling the target to the shotblocker. You need very good individual perimeter defenders to really shut down penetration, and you can cover for that with a sound defensive plan somewhat, yet if you're not cutting off penetration you need to funnel the target to someone. We don't have that someone right now, which is why the Cuz as a defensive anchor comments are reason to be a little nervous.
