While absolutely a wonderful thing that Ole did there, at this point there's a strong argument that it wasn't a 'footballing' element in his development that Ole contributed to. Ole managed (ha) to steer Rashford away from the Pogba/Lingard influence.
Yes, these would be the executive-level decision-makers mentioned earlier. You're right having the appointment be 100% fan-selected is pretty zany. And assuming 'proper' football knowledge within the executive level, then fan opinion and executive opinion would largely overlap, which would make it (fan opinion) a bit redundant.
But right now, with the board being comprised of the people it's comprised of, it does seem fan opinion being reflected might help the 'football-wise' elements among the executives. Arnold, if he's as great as you've been posting, could take such a thing to the board and go, 'See, the fans are suggesting these people, too.'
Again, in an ideal world, he shouldn't be in such a position. But the board are Glazers and their friends who all have a track record of doing poorly in school and in business and who extremely likely have no idea about anything about football, so fan-opinion could help the guys running the football department (not to mention up until very recently, we had Edward frocking Woodward running the football department).