I like the Prime setup. While I cannot think a lash whip would be better, the Prime I think is I6 on the charge so not a lot will be going faster than it and
LD on
3D6 is cool for the boneswords.
One problem I've noticed is the Hormagaunts have the special run move and fleet, these won't work with the Prime and will stop that unit from assaulting as quickly.
I think the rest is ok. Run it and see how it is