I keep seeing posters pop-up with 'why do we need a DoF?', 'why is structure so important?', 'why doesn't the manager just sign player X, Y,Z'? - all of which are very outdated statements to be making in modern football
The reasons clubs appoint these people and have structure around the manager;
1) To prevent success/failure being totally dependant on one individual
2) To ensure continuity of vision i.e. if you want to play the 'United-way' or the 'Liverpool-way' or the 'City-way' or the 'Barcelona-way' you need to ensure that this comes from above and players are not just signed on the whim of the manager, as in the 90s
3) The modern football manager has to much on his plate to do things like handle contract negotiations, transfer negotiations and watch hours of video footage to scout players from the Dutch 2nd division
What we have seen at United over the last 5/6 season is a classic example of how not to run a football club. We've now had four different managers since SAF, all of whom have a different style, different objectives, different man-management techniques and who were at different stages of their career.
The result of this is this 'Frankenstein' of a squad we have put together whereby we have young, inexperienced lads who are not quite ready thrown into regular first-team actions with Moyes' panic buy(s), LvGs 'multi-purpose footballers', Jose's giants and SAFs squad players! How ridiculous is it to see a midfield containing Matic and Herrea together with wingers at full back, a wannabe-striker on the LW, a slow, technical #10 out on the right and our highest-earner sat on the bench!
If we are ever, ever going to achieve anything again we need to get over this 'Cult of the Manager'. I get it, because for a long time we were managed, albeit in a different era, by a man who will go down as possibly THE greatest ever. However, I think the fact that we were so successful under that 'structure' for so long is actually hurting us now because whilst our rivals where modernising we stood still. Let's be brutally, brutally honest without our rose-tinted glasses for a second...as great as SAF was, and I'm not knocking what he achieved, United where miles ahead of our rivals in terms of resources and power in the 90s/00s. Therefore when we did go a season or two without a trophy we would just flex our muscles and buy the best players in the league, that's not possible anymore!
To put it another way, look at both City and Liverpool - Pep and Klopp could leave tomorrow and the clubs would continue to move in the same direction. The signings, the ethos, the tactics, the style etc....would be continuous and the 'only' thing that would change would be the name of the bloke who picks the XI and makes the subs!