I would have liked Alexander better if he found some balance between Klingon desire to be a warrior and the peaceful desires he learned from his mother. Maybe something that suggested the events in the future of Firstborn, only with some twist that helped him avoid his original mistake.
Alexander didn't have the skillset to be a warrior so he could have also found some other skillset that could be useful to warriors. Like, if DS9 hadn't established him to be a bumbling moron he could have been a competent medic or engineer who was berated for being terrible at combat.
Or they could have, I dunno, not jumped him in age from 8 to 14 and included him in some other way in the story that was not making him a bumbling idiot.