There's a lot of things that can change within the core formation but changing the formation is very disruptive to the whole team, we only do it in sheer desperation and it never seems to work.
Very, very few teams in the top two divisions play a 4-4-2, it fell out of favour 12-ish years ago and has the lowest % win ratio in the PL. It's now nearly always possession-based, playing three central midfielders and one central striker, either in a 4-2-3-1 (as we did until the beginning of last season) or a 4-3-3 – the one with the highest win ratio. In the Championship, Millwall have stuck rigidly with it and WBA seem to use it quite a bit; I can't think of others. I can't recall the last time we lined up like that and, with our young squad, it's probable that none of our players have ever played that way.