I'd suggest that the boards he has worked for have tried to protect his squads as much as possible as they are aware that stability and continuity is the best way for them to achieve any success. Something that AVB has never shown in management, out of the 5 clubs he has managed, the only one where he has lasted more than 1 year is his current club but he has already announced he will be leaving at the end of this season. Everton as a club cannot afford to change our management setup and spend money on the players the new manager will want if he's only going to stay 1 or 2 seasons, an argument I was making recently to someone who had suggested Koeman as a replacement.
OK, he's won titles. One at Porto, who have won the league 7 seasons in the last 10 and Zenit who have won their league 4 seasons in the last 8. Fair enough, a league win is a league win, but it's hardly an unexpected achievement from an underdog, like Wigan winning the FA cup for example.
You will have to explain to me what tactical discipline is, I don't know what that means.