Rock Clones and Golems are good defenses, true. But the magnetic forces of Kazkekage can recycle sebons and alters its directions for next use. Also changed its flight to "super sonic" speed, which needs Onoki to produce the defense before it reaches him, which I dont see him escaping. Also all his defenses will be sliced up by water jets.
Sasoris flight speed should be superior to Deidara, Gaara, and Onoki (as they are even in flight speed) since IS can increase its speed faster then Gaara's sand usage. If you think Deidara and Gaara can escape its range, Sasori would be no different. If you dont, then it doesnt matter based on the fact that Sasori has faster execution to his attacks then Onoki