The Raid I need when a disk get failure (not so unusual)
If the disk dies you hopefully have a backup of the data as well as the FOG image to deploy that to a fresh disk in a few minutes.
Not saying that RAID is useless. Not at all. There are setups where RAID is great. But with FOG it’s not as simple if you want to use such things.
The setup as you have it now seems to be spread across three MD/RAID containers. I have no idea how to handle that in FOG. Simply setting host primary disk will probably not work.
I have not played with RAID setups yet and so this is just from the top of my head. Maybe there are other users with more insight into that topic. But I just want to give you hints trying to make this easier for you.