It is not unusual for clubs to release a video interview after a managerial appointment.
Pellegrino, Puel, Koeman, Pochettino, Adkins, Pardew etc etc all had one.
To reach the quarter finals requires being in the top 2 of a group with Belgium, Panama and Tunisia and then a last 16 match vs one from Poland, Senegal, Colombia & Japan. We are not so dreadfully poor that those set of results are unlikely.
That is not reflected in their wage budget...
2016/17
Ajax wage bill = £35m
Saints wage bill = £112m
Saints can blow Ajax out of the water for wages. I doubt they'd come close to what we pay Tadic.