4-3M-2W-1 is indeed the best counter of 4-5v-1 when it is of equal quality to up to 10% disadvantage. Without 3 MCs is not an issue, as you could play both ML & MR close to MC region instead. The rationale is just 3v2 in central midfield to win the possession battle there. Opponents not playing any wide midfielders also mean your ML & MR would be having an advantage in both areas anyway. Stick to that would be fine as well.

If opponent’s ST is outstandingly strong when compared with our DCs and also opponent also has one of the fullbacks way better than our corresponding AML/R, it may be safer to play an extra pulled-back DMC to 3-man-mark that ST plus controlling the DMC area and only attack via your stronger flank, as that weaker winger is unlikely to win the duels and has a far lower chance of scoring even when he is playing at the ‘correct’ location. This way we ‘only’ sacrifice 1 opponent’s flank area but controlling all other parts of the pitch. Key of match control is to avoid that DMC area, unless we are going to overload with 2 AMCs.

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Generally, do not play both ML & AML so tightly as they tend to ruin passes in between. If attacking wide areas with both ML/R + AML/AMR seems more beneficial in certain circumstances, playing the AML & AMR aligned to ST is even better in terms of taking chances. DL & DR could pull wider to help further if not affecting defensive duties.

The back-up plan in last 20-30 mins when chasing the score could be a switch to 3-5v-2 (flanks), 3-1-3-2AMC-1 (middle) or 3-1-2-2AMC-2 (middle), depending on your players position availability and in-game opponent’s defenders ratings and yellow-card status (attack the weakest and most 2nd-yellow-card-prone zone).

Wish you the best of luck!