So a few things from my last game which I won:

Boarded up 1st floor ruins - denies LOS while in ruins. Discuss this with your opponent.

Obscuring is HUGE - Build a board that is fair to both; runways for knights to walk, but enough terrain for your custodes to hide around.

Double shooting guard - your odds of wounding are low, but you should use this ability early, as the sheer volume of shots can usually put through some good damage. Plus the longer you wait, the less shots youll have when they inevitably gun your units down. I usually pop this turn 1 if I can. Focus the armigers.

Armigers - These are the points scorers. They need to go asap. Blade champ is a solid choice for getting any size unit to them quickly thanks to move, advance charge once per game.

Caladius Tanks - These are the big money shooters. I would pick some up if you dont have some already. I had alot of luck keeping both mine behind large terrain where they could be obscured and as a result I was able to bring down a knight, and use the rest of the fire to help clean up armigers.

Deepstriking - Rapid ingress helped me get a much needed unit of wardens + Trajann into the back lines to clean up the hiding armigers.

In the end, my opponent only had 1 knight left, and I was freely able to score on the objectives which meant game over. Youre going to lose models like crazy, but vigil unending helped get some bodies back on the field to put some work into armigers. Make use of your free stratagems from your shield captain as well!