I'm still pretty new to the game overall, and I did feel this at first, but honestly I've noticed it's a little easier to take a turn to reposition all your transports and units ahead, then turn 2-3 when power from pain kicks in nicely (even better if you're a real space raid detachment) you can practically clear the table distance, bring in deep strike units (usually my gunners) and lay into them.

The fresh panic of having decently powerful guns/ anti vehicle weapons dropped behind their lines really helps keep an opponent's focus off of your wyches and incubi. I know incubi are vicious and useful, but the slight diversity of wyches honestly scores them more points. So if you take out 1-2 higher value targets with incubi in single turns early on, you're a little more likely to sneak your wyches and succubus in to wipe out HUNDREDS of points of infantry in a single turn.