Because defenders can camp in the paint indefinitely in FIBA play, your must prioritize mid-range jumpers and deep pick-and-pops. Man-to-man defense in IBM 23 is dominant, but only if you adjust your "Help Defense" slider to Late. If you leave it on Auto , your defenders will sag into the paint, conceding the dreaded "FIBA Floater" zone.
For more community-driven tips and real-world mods, you can check the IBM23 Steam Discussions International Basketball Manager Wikia for your team's current roster? international basketball manager 23 tactics