I agree that Ronaldo is the ultimate. Karagounis as well, was with the NT until 37.
I see Sokratis much closer to Ronaldo than to Messi in terms of attitude though. Ronaldo always had a team around him. A team like he was used to at ManU and Real Madrid, no, and that must have been frustrating in its own right. Nevertheless, the frustration Sokratis is feeling with the stagnating/declining Greek NT, infected with politics and ego, has surely taken a toll. I think Sokratis is more irritated with EPO and the coaches they hire and money they invest, more than anything.