One thing about it. If Dallas were to win the Superbowl with Big Mac as the HC......Not many would say that Big Mac did it- not Jerry Jones, like they did with Jimmy.
Jerry doesn't have to worry about that one with MM. Of course he doesn't have to worry with winning the SB either, but you can't have it all.
And no, unless things were just perfect, I don't think MM could win the SB. Give him an elite QB, elite D, elite line, and a good RB\WR room with elite coaches going above and beyond and yes, he could win, but so would many other coaches. MM seems to do one thing a HC has to do well....motivate his players. He is also good at schmoozing the owner which seems to keep him around. Discipline of the players on the field and off seems to be weak. Keeping great coordinators ahead of the curve is horrid. Making sure all the players are in sync......not good. So no, I don't think MM will take the Boys to the SB and win it all with one of the worse GMs in the NFL, who should have been fired from that job long ago.
Hire Mike Vrabel and get started curing the culture with insisting on discipline.