I think he's fairly complex here - I mean, hiring his crazy half-brother as an assassin to get rid of his old friend, who was acting as guardian to his daughter, all so he could ultimately have his daughter off his brother is pretty twisted, all right, but look at his reasoning. By his way of thinking, this is a reconciliation, as close to an act of love as he's capable of - he's trying to bring his daughter into the family business. Sure, by doing so he's severely screwing up her life, but he doesn't see it that way - he's proud of his career as Deathstroke, and he wants his daughter to share in the glory. It's twisted logic, no doubt - a logic that winds up causing three unnecessary deaths. But you can't say there isn't a positive sentiment behind it.