The instructions says for Values that do not exist, set values to closest valis row. This, I was assuming was for multi-row formula tool. For 3mo average and 10rm 6mo average, it used just that. For all other 6mo average, it calculated only on the months available and divided by 6. ie single month value divided by 6....2 month values divided by 6...etc.
For sorting, the original data found in the output is sorted to original column order. For 3mo and 6mo averages, they are sorted in alphabetical order.
The origin of the 3mo and 6mo average name are not helpful either.