If we've had to replace our main midfielder pretty early in 3 of 4 League games, even if it is just for 'tactical reasons' as you say, then surely something somewhere isn't quite right?Vs Villa it was a tactical switch (to bring on a more attacking player in Eriksen).
Vs Palace likely to be to get Ndombele some game time before the CL game.
Vs City again it was as much tactical as anything else.
Winks just does not have the required traits to play the position he's being asked to play; period. One of the main reasons we look so vulnerable to counter attacks is because we have no decent defensive midfielder protecting the back four. We've had in and around 70 attempts on our goal from opposition teams in the opening 4 games. Compare that to Liverpool(38) and City (31), neither of whom have hugely better defenders than us but most certainly do have much better defensive midfielders than us, and you can see why it is a problem.
It's such a massively important position on the pitch that I'm quite frankly shocked we didn't even appear to attempt to address during the summer.