There's the healing factor, super strength (Everyone forgets that one), slight super speed (Not Flash level, but faster than a normal human), super fast reflexes and reaction time, the ability to use 90% of his brain, the fighting and weapons expertise, and he's supposed to be a tactical genius.

If these had been relatively new dvelopments, I'd agree with the complaints, but he's been that since he was introduced. It's like complaining that Lex Luthor is too much of a genius, or the Joker is an insane criminal. He was created specifically to fight entire super teams, to be the Titans' Dr. Doom without being a Doom knock-off. Personally, I think it's to Wolfman's and Perez's credit that they came up with such a unique take on the concept of a super team's arch foe. Any issues with him winning those fights with the Titans... Well, you'd need a time machine to hop back to 1980 and take it up with Wolfman and Perez.

That said, Supergirl should have no problem with him. But then, she shouldn't have had a problem with Cassandra Cain, either.