threat. He's much more comfortable within 5 feet of the rim, using his strength and quickness around the hoop. He's the perfect 5 for Rose's offense. Mika will be allowed to develop his mid-range game playing the 5.
Dastrup is a natural stretch 4 with the skillset to match. I think you might be underestimating his athleticism, too. He's probably not as quick as Mika, but he's perfectly capable of putting the ball on the floor and scoring from anywhere inside the arc. Dastrup has much better handles and a much better mid to long range jumper than Mika does.
Obviously, I'm not Dave Rose. But, if I were the coach, Mika/Kaufusi would be playing the 5 while Dastrup/Davis would be playing the 4. If Mika plays the 4, that really only leaves Hamson to back up Corbin at the 5. I don't see that happening. I can almost guarantee you that Mika will be playing the 5.