In modern football, width is provided by the wing backs with wingers acting as inside forwards. In fact, Liverpool's wingbacks have a record number of assists. To achieve that one has to have a solid central unit (GK, 2 CB and DM) as they need to cover for the space left by the wingbacks.
Ole opted for an outdated system with 4 defensive defenders. The advantage of that is that our defence leak less goals which makes the manager looks good (imagine spending 130m on a defence that still leaks goals) However it also put huge pressure in midfield who have to basically shoulder all the creativity themselves. I dare to say that what we're asking from our midfield goes beyond to what Sir Alex asked from the treble side and the 2008 side. Those teams had the likes of Irwin, Evra and Gaz in them which could go forward and create chances.
That explains why Ole wouldn't want to compromise on attacking midfielders. He wanted Sancho and Grealish as he desperately needs their assists and goals. He also can't afford weakening the defence by playing 2 attacking wingbacks because he knows that Lindelof and his beloved Maguire won't cope with that. They need the cover provided by AWB and Shaw. Scholes on the other hand think that the solution is to add a goal poacher upfront. That won't increase creativity but it would certainly increase the chances to goals conversion significantly.
In my opinion both legends are papering the cracks. United need a GK, 2 CB and a DM that they can rely upon. That would in turn allow us to utilise 2 quality attacking wingbacks. Greenwood, Rashford/Martial, VDB/Pogba and Bruno would then focus on creativity and that would lead to goals. In short Ole wasted 130m and he wants some 250m worth of talent to cover for it.