If you are going full Kabal then generally, you don't want to be in assault, warriors just can't hack it in there. You should be doing your killing from afar with splinter and darklight.
On full squads then I believe that splinter racks are probably worth it, but this does limit your raiders movement to 6" if you want to fire those weapons. I would probably head down the 5 warrior/blaster option, either in venoms or raiders depending on whether you want more AT or AI firepower. If you load up on blasterborn and ravagers then I'd suggest you'd probably be looking at a mix of venoms and raiders, at 1750 I run 5 venoms and 4 raiders through the list. This gives a nice mix of AI and AT from the transports.
The thing is you need enough AT to supress enemy tanks, and open up transports so that your splinter weapons have something to do. I aim to have as much AT as possible in lists, (if there is no vehicles left to shoot it can be used on elite troops/IC's), something like 31 at 1750.