If we set up overly defensively then we've not got the freedom to please everyone because we're not attacking enough. We were solid defensively last year but eventually even the "weaker" just promoted opposing teams started to smell blood and line up accordingly. they would have the balls to take the game to us (even at home which is unthinkable).
As good as you are defensively, there's always someone in today's PL teams will more than likely find a chink in the armour or just plain get lucky in 90 minutes.
This is when the problem starts: an opposition that is not afraid of you goes ahead, home fans turning against you, lack of belief from some of the worlds most expensive players (seemingly purchased to become defensive cannon fodder for Monday mornings press).
If we lean more towards the more attacking formation (pushing the strengths that the majority of fans want, and pay, to see) then we will sacrifice a fair few goals at the other end initially but Jose, and we, will buy ourselves time to plug those holes in subsequent transfer windows.
It's what Liverpool were criticised for last year and … oh look they fixed their defence.
I don't think it's about being overly physical. It's intent. Hazard will run head on into Fellaini or Lukaku (with no hopes of physically overpowering them) but 9 times out of 10 the foul will go the way of the player trying to "play" football!