I think Di Vaio is low because he has not proved himself yet to the fans.
Thuram is low, well last year he did not impress, and maybe that is still in our minds, also i did not like his reaction when a Juve fan tried to take his shirt off on the last day of the season, he didn't seem like a man that was happy to have won the scudetto..unlike the rest of the team.
however, he is much better so far this season, so if we did a similar thing in the future, i think both would be higher up.
as for birindelli, i haven't seen him play much, but from what i have seen he is a hard working player, unfortunately not blessed with particularly good technique..but still i only gave him minus one. i think those that gave him minus ten..I think this is harsh when you have the useless baiocco around