Truly it is a conundrum. On one hand these soldiers were only doing the job Ceaser commanded them to do. It isn't their place to question the orders of their leader. On the other hand, Pontius Pilate did say that Jesus was innocent of any crime. If these soldiers trusted their conscience they would have known that they would be torturing an innocent man and chose to, instead, face Ceaser's wrath.
If the soldiers had not beat Jesus like they did surely other soliders would have done it and the insubordination would be punished.
Really, your question is similar to what of the fate of Pontius Pilate? His hands were washed away of the blood because it was techinally the Jews that sentenced Jesus to death, Pilate was only executing his duty to the state. If Pilate trusted his conscience Ceaser would have him fired and replaced and his successor would fullfill his duty to Ceaser and God's prophecy. So was Pilate in the wrong to allow Jesus to die?
Than going off of that question, we can ask ourselves what of us here in modern times? Is a soldier responsible for following the bad orders of a bad commander? If the soldier was lied to and drone striked a wedding because he thought it was a terrorist hangout, is that soldier responsible for the civilian deaths or his CO (or both?)
Did any of the Church Fathers or saints write about this?