Scholes started off as a forward, surely they can be coached into those positions? I would say they are two of our most intelligent players, couldn't they be coached for those positions?
You write as if any player can be taught any role - to a league winning level of quality. That is not so. A top class forward or no 10 can sometimes adapt to a different kind of role and play it to a world class level, but it is the exception (Scholes) and far from the rule Rooney), and in the few cases where it works, it is because the players special attributes can be as easily expressed in the new role, and his weak or mediocre qualities are not much asked for.
Scholes had a weakness when it came to speed and another in muscle power, but this was as much a problem in a winger role or no 10 or striker role. He had a talent for discipline and positional understanding that helped him complement that weakness in midfield, particularily when he had a partner with equal positional awareness (Carrick) who didn’t force him to cover much space fast. He had a strength of quick brain and overview that worked as nicely in midfield, and a precision of touch and pass and a discipline of focus that allowed him to escape pressure 98 % of the time through quick passing.
Pogba has played in midfield two’s for a considerable part of ten years, and he still is caught out of defensive position many times every single game. It’s not lack of motivation, it is just a weakness that doesn’t go away with teaching. He loses the ball more than once every single game in dangerous positions, like he did for the last goal we shipped. Of course he hates that and desperately would want to be able not to fo it. He just can’t seem to learn it. He has the technique, but probably not the quickness of mind and overview. Countless times he slows play after coaches have stress that we need to up our passing tempo, and it doesn’t go away. He’s 28, it’s a weakness, you can’t give him a role that demands him being able to be a metronome, or where vulnerability to press is critical, or defensive positional awareness at highest level is a bare minimum - like any kind of a 6 role.
Similarily for Bruno, but that’s covered in a post to jprouve just above this one.
sense of positioning, quickness of mind, tendency of responsibility and focus are partly talent, partly trainable. You can’t coach someone to become world class at a skill if it is just not there in the mid twenties.