How do you adjust accordingly if you dont have a great rebounding team at all but a fast and athletic one? Do you have to go -4 or -5 all the time to help counteract this? My team has very solid DEF ratings. I run flex, man to man BTW.

Well, you can go uptempo, since you have more speed and athleticism than average and you aren't going to win the rebounding battles shy of one guy. I'd be reticent to go too negative: you may get a few more rebounds, but I don't know if it is worth the risk against balanced teams. Going -2/3 will help some, but I'd just rely on your quickness to score and defend and let the rebound fall where they may.