I like the way we were more flexible in our set ups in the last few games, you need a basic system to fall back on but the ability to change it makes us a better team, we definitely need 1 of the cb's to push in to midfield when teams just leave 1 up against us.
Yes, I agree. The problem we've had in numerous games such as the recent game against Arsenal and the away game vs Chelsea is when we've been outnumbered in midfield, part of the reason for which is that they've had one up front against our 3 CBs. That inevitably leads to an overload against us, most commonly in CM
So Dier pushing out in front of the other two CMs is a clear evolution and presumably to counter this. The obvious risk is that it leaves a gaping hole between Romero and Davies/Lenglet, but probably they're alive to that and narrow that gap it should work