Robert I don't think VOA entries have an exemption from being requested to show cash. It says it in the very regulation you are quoting- "Having appropriate means of living. (10,000 Baht/person, 20,000 Baht/family)"
That's the same for the visa exemption, incidentally, but in practice they demand 20,000.
As written in the law, this requirement to have
*****
k applies to visa exemptions, visa entries or VOAs, as far as I am aware.
The VFS Delhi site lists the same financial means requirements for both VOA or visa exemption.
The Delhi embassy says: "Applicant must carry sufficient funding (at least 10,000 Baht per person or 20,000 Baht per family) and provide proof of accommodation in Thailand."
He may not be asked, but I'm not sure it's the case he can't be. Most visa exempts aren't asked either.