An underappreciated strength of SAF is his ability to turn players on a budget into real United players, and many of them performed weekly although they were not considered the core first eleve, while also changing player's position effectively.
A then 35 year old Teddy Sheringham, Park Ji Sung (a marketing gimmick I thought initially), Tom Cleverley, John O'Shea, Antonio Valencia (only Wigan experience that time) all were able to perform when called upon. Even David Bellion and Alex Butner looked decent under him. And, Scholes, Smith and Giggs had their positions changed.
Now we have too many idle players sitting around doing nothing while the team requires holes to be patched. Under SAF, could Rojo be used as a decent attacking full back? Could Lingardino be used as a deep lying playmaker? Would Dan James be successfully slotted into both wings? All these would be possible under him.