Is my 4-3-1-2 good against 4-4-2?
Yes it is quite good against 4-4-2.

Although the initial formation you showed a screenshot of, was quite a decent counter to your 4-3-1-2. With this in mind, the guy you're playing might be putting up 4-4-2 to trick you into thinking he'll play 4-4-2, and then change his formation just before the game starts. If I was you, I'd assume he's going to run 4-4-2, but check his formation 7 or 8 minutes before the game starts, to ensure he hasn't changed it.