Black should not waist time improving White's position with 4...NxB. Better would be eg 4...c5 with a interesting and level position.
It is perfectly playable. A practical problem will be, that some Dutch player play 2...e6, so you will need another answer to that. It could be 1.d4 f5 2.c4 e6 3.Nf3 Nf6 4.Bg5 witch you will also have after 1.d4 f5 2.c4 Nf6 3.Bg5 e6 4.Nf3. Capablanca and Jusupov have played like that.
Why this position is good for white? How can white exploit this line?