What Are the Requirements for a Non-O Visa and Dependent Extensions in Thailand?

My wife and I are in our last year of the 5 year elite visa. Next year, as we are both 50 now, we are leaning towards getting the non O visa from our home country. At immigration this week the officer said we would both have to get the Non O to start with , have a total of 1,600,000 in the bank to cover us for 2 x 800k but then later my wife could use the marriage certificate and we would need just 1 x 800k in the bank. I was under the impression my wife would be covered by my Non O and subsequent retirement extension from the start.