I think that the specific individuals, whilst they clearly will have an effect on the performance of the structure (whether that be within coaching / medical / transfer etc parts of the club), it is clear that the performance will naturally be judged on the performance of the teams they are connected to, and there are examples of execs that are heralded at one time or another moving then either underperforming or just no longer 'over-performing'.
They fact is that the club needs to agree what the values are, then work out what that looks like from a data point of view, then make that happen in the youth structure and on the training pitch, then give it time to breathe and keep tinkering to improve it.
Previously, this would've been all down to the manager and likely coaches giving it the 'eye-test' etc, however now we have data and can lean on that to both see if it is working and also ensure continuity if and when staff members (from coaches to managers to execs) leave.
The issue we have is that we keep chopping and changing the values (i.e., different managerial playing styles) without giving it time to bed in and then review it and improve it.
I am really hoping we are going to just keep moving in the same direction as if we do it will improve, because we will review what is going wrong and put it right, and that will mean it will get better over time, and that includes the exes such as Murtough and Fletcher, tellingly, McTominay referred specifically to Fletcher in his post-match interview after Brentford.
Overall, Murtough and Fletcher are just the heads of their respective areas, and if the teams below them are working well then they will look like their doing their own jobs well too, it's hopefully the start of a period of making this project work without changing direction (again), we need to get our heads down and work through it, retaining and acquiring players that can play the system, looking for youth players that fit the system ,weeding out players that either don't fit the system or had bad attitudes, if we do that we will improve, and with the £££'s that we spend we will then outperform other clubs accordingly.
Teams like Brighton haven't reinvented the wheel, they're just sticking with the plan and constantly reviewing it to improve it and to reduce bad habits... a couple of execs don't make the difference, it's the culture of the club as a whole that's important!