If you look back a few posts you’ll see I took a Raven Guard list to LVO and DM3. Both lists were based on a Talon Strike Force, with a Battle Demi Company and Shadowstrike Kill Team. The heavy lifters in both lists were 3 tooled up Vanguard Squads. This relied on the Vanguard’s ability to come in from reserve, any turn I chose (including turn one), and assault out of deep strike. The lists differed in the Vanguard’s delivery mechanism.
The key is landing the Vanguard without scatter so they don’t mishap and are in guaranteed charge range. As part of the formation, you need to take 2-4 units of scouts. If the Vanguard deep strike within 9” of 2 of scout units, they don’t scatter. In the LVO list I had 4 units of scouts in Land Speeders Storms. I infiltrated them, scouted them into position, and deep struck off the LSS’s hulls. However, the problem was, if I wasn’t going first, the scouts needed to survive a turn of fire before I could bring in the Vanguard. Given how fragile Scouts are (even in Land Speeders Storms), first turn was pretty important.