Advice on starting a cult

basically its about getting as many units into raiders and ramming them down your enemies throat.
Pick their weaker flank and overwhelm it.
move 12"+ 2D6" for aethersails and then turbo into range (preferrably behind LOS blocking terrain/ruins/buildings etc) for an assault next turn. he can't take out all your threats in one round of shooting (especially if you get your 4+ jink or 4+ obscured cover saves) so at least something is gonna make it into combat.
Put it this way, if you leave groups of wyches/bloodbrides in the midfield/own deployment. they are dead + stranded and will not be useful. if their transport blows up in the enemy deployment zone, they stand a much bigger chance of contributing to the battle.

i feel it works better with some non-mech units to help pressure the enemy to split their fire.
Beasts and reavers are both fast and can take some punishment, if you run a talos up aalongside the beasts, you really start forcing the enemy to make decisions about where to pour his fire.