I don't think your team is THAT slow but it is THAT unathletic (to tired to spell that right). Your Centers are slow, I think you need speed at the 5 position in DII. If you can get rebounders with a 40 or 45 in SPEED I think there is a benefit.
As Tianyi said, you need more STAMINA as well. I like to play 12 on my press team. I don't let them get to tired, I set their rest at fairly fresh.
As your IQ goes up the fouls will go down.