I don't know that Sasha, or Nicky, would have been better at their "jobs" has Alexander II lived. As with George, Sasha was not "meant" to be Tsar, he became the heir after his older brother died. Unlike George, Sasha had real power he was unsuited to weld. As he was unsuited to reign, he was totally incapable of teaching his son how to handle the position.
One parallel between Sasha and George that I found interesting - they both married their older, deceased brothers' intended wives. Suitable wives must have been in very short supply!
Cat