I have been highly successful with this style of tactic in FM20 and this is yet another tactic from a long line of my top tactics. As you can see i have now gone with a 2 striker formation as i have been asked for this by many. This is a very high scoring tactic that i am sure all will enjoy.
The fact is that the 4-3-1-2 lineup requires players to have special skills and good tactical training. Central defenders must feel confident in possession of the ball, have a good first pass and be able to hold the line high. Defenders and midfielders must have fitness and stamina as they will need to cover alot of ground. It may be worth while having a large squad so you can rotate players.
You could say that this tactic is a 4-1-5 formation when going forward and the advantage of this is the different variety of attacks will cause the defene all sorts of problems. Give the tactic a try you will not be disappointed!
This was the results of the test i ran in my test league which scored really well. As you can see with usnig a pretty average Milan team we still finished way above expectaions.