Attacking middle or flanks

[Toxcatl]

I know what you mean. But your example is pretty clear. Let me put another example. What if the oppo play a 4 4 1 1? Make sense if I go 4 1DMC 3W 1 1, cause he's got no DMC and go through the middle, or should I go the flanks?

4-x-4-x flat formations are the hardest IMHO. Strong defence and no weak spots, especially for 4-1-4-1. You can try the middle, flanks or mixed, just use positions your players play the best.
But again, if you use AML/AMR, don't go through the middle. If you want to go through the middle, don't use AML/R.

As for 4-1-3w-1-1, it is not a counter-formation for anything. Use 4-1-4-1 flat instead and attack through the middle or mixed (MC/L/R are more attaking players than defending).