As ive said before, make the 4 piece needs to proc the 2 piece along with the hatred gens.
Now as is, the 6 piece is weak. It needs to be buffed or here is my idea. For every stack of momentum, thats how many time you fire your primary. So when you are at 5 stacks, you fire the primary 5 times while strafing, when you are at 10, you fire 10 times while strafing.
This is my post on how we can fix the DH while keeping the idea I believe they were going for which is a stop and go type build. More explanation in the post.