Actually, this is still as-is, in an area where the basement is being totally redone (I mean, old pipes being dug up, etc.)

The install isn't more than 2 or 3 months old!

Question: This panel feeds some subpanels, using 6/3 AC cable. (No individual ground conductor). Is that OK per code? If so, would you rely on armor (assuming the bonding strip was properly terminated with the armor) for a ground?