How RAID data recovery actually works
Three stages, and the order is the whole discipline.
Every member drive is imaged first. Nothing is attempted on your originals. Weak or failed members get hard-drive-recovery treatment - board work, head work, careful hardware imaging that works around bad areas - until we hold the best possible copy of every drive. From that point your originals are out of the story.
The array is rebuilt virtually. A RAID set is a puzzle with parameters: drive order, offsets, stripe size, parity rotation, and which member went stale first. We determine them analytically from the data itself and assemble the array in software, from the images. That's why lost labels, a dead controller or a missing enclosure aren't fatal - the parameters live in the data, and reconstruction never writes to a single original drive.
Then the filesystem gives up the files. NTFS, ext4, BTRFS, APFS or HFS+ is repaired or parsed from the reconstruction; VM containers are opened; the folders you actually need are extracted and verified. And the honest limit, stated plainly: where a completed rebuild or re-initialisation has genuinely overwritten data, no lab can conjure it back - the assessment will tell you what survived before you decide anything.