Ok, I have more datasets, they show clearly that: type 5 can be wrong, and sometimes is.
They also show that type 16 can be, and sometimes is, wrong.
The only things that always seem to be right are type 17, the individual memory device item.
the data in Array-X can't be synthesized reliably from the type 17 data unfortunately, and it's often right.
So maybe the best thing to do is to somehow indicate not to trust the data in Array-X line. I believe the number of devices is almost always right, ie, how many slots etc exist, so probbly the voltage is right usually, so it's just the capacity/max module size that are in question. Hmmm, I can add up the installed memory as inxi calculates the data, and if it's greater than the listed capacity, / and or if the individual module sizes are greater than the listed max size, dump that and show an error message, maybe? like: 32 gB (est.)
While annoying, this is the exact type of issue I was hoping to find.