I looked over potential allies for daemons and figure this is one of the better ones. First off let's start start off with any daemon can benefit from soom Daemon boons.
In this case as is if given an improved save with tome of true names than they can have a +3 invulnerable save. Give them mark of Tzeentch you now have a solid +2 invulnerable save for theses guys.
Put them in a rhino to get them to point B. Before they embark give them the +2 invulnerable save, so even if the rhino dies they can easily shrug of gun fire.
As a side note Instrument of Chaos works with all daemons. Like obliterators which you can get in without even rolling for them if the instrument bearer ds in. With icons any deamons only deviate d6 inches from the icon.
The warp storm table benfits/ hurt you as well like +1 invul or - 1.