Being upfront, I think Smalling is an excellent defender and has got a lot of unfair criticism because he is outright ungainly to the eyes on the ball. If Smalling is the only player we can realistically sell from Rojo/Jones and even Bailly so we can afford to get an upgrade to Lindelof for a partner for Maguire, then fine. But, if we are selling to raise funds for a forward, then to me that's a big mistake.
Yes, Ole wants to play out the back. I just don't see how putting Smalling changes that. Watching us all season, Lindelof's role was recycle the ball to midfielder or Maguire. As for being able to handle the press, looking awkward on the ball aside, nothing I saw gave me the impression that Lindelof fares that much better when we get pressed, as a team in fact we don't handle it that well overall.
The playing out the back is a red herring anway, our issue is being able to defend a lot higher up the pitch with a a Lindelof/Maguire partnership. The lack of confidence in being able to defend higher up means they sit back more and that means the midfield has to play deeper, which then makes it more difficult to connect midfield to the attacking 3rd. And when they do play higher up, the two of them poop the bed every time the other team breaks.
As for the good defensive record last season, we played with a lot better balance overall in the team and we defended better as a team especially second half of the season. Ole kept talking about how Martial is working harder and even the defenders talked about how so much of it started from the front. Even during our post-lockdown run, the one thing all the pundits said was yes they look attractive but, that backline, it does not inspire confidence. Think Smalling would at least fix that in the short term till a CB with better defensive capability but, with his ball playing ability can be found.