Re: DS9 ruined Alexander Rozhenko
Well, even if we didn't get to SEE it, we do know that Alexander had to have changed off screen since he was promoted to Weapons Officer. On a Klingon ship there are only two ways to move up the latter.
One: Be exceptional at your job. Two: Kill the guy that is your immediate superior and take his job.
I seriously doubt that Alexander would do the second option that soon after seeing him at DS9 but in either case, we do know that he became a "True Klingon" in one of those aspects.
No, there was a war on and in war you take casualties. Even Worf said, "They were short on officers" referring to Alexander's promotion.
"I was never a Star Trek fan." J.J. Abrams