Ole is a highly underrated manager. Just look what he achieved with Molde. They beat Celtic, Ajax and Fenerbache in Europa League where they won their group. Molde as a city only have 28 000 inhabitants.. quite impressive
And at the knock out stage they even beat Sevilla at home (but lost on aggregate). Sevilla won the EL that year. Molde actually played well in Europa this season as well, and looked like the better team in the play-offs against Zenit, although they at the end lost 3-4 on aggregate. Based on budget, all these teams should easily beat Molde any day of the week.
He had a difficult spell at Cardiff, and he only occasionally succeeded in making the players perform a far too ambitious playing style, and words like "inept" and "naive" were frequently used by the Cardiff fans. How can you possible make Cardiff dominate games with possession in the PL. He really was the wrong appointment for a club fighting relegation.
This could be a worry, perhaps, when you are up against teams like PSG (or Tottenham away, for the sake of it), but the way he has set up Molde to play in Europe (especially away), has made me believe the underdog´s game is something he has added to his repertoire. Solskjær is past the point of being the rookie some seem to believe he is.
Then time will show if the Scandinavian way of leadership (you could say) is a good match for United. But the world is changing, and players may not respond to a "tough guy" the way they did only 10 year ago.
And if I were a world class defender (like you need), why would I not be tempted to sign for United with the atmosphere surrounding the club right now? For attracting players, I think Solskjær could be a pluss for the club.