This is a life changing tutor. After reading how one uses the RH, I shall now and forever use the term "sprinkle" for how I disperse chord tones about the banjo.
Yes, I will be using "sprinkling" in place of "rolls" from now on.
The numbering system is a little strange. I have not sat down to focus on it but it looks like he numbered the chords as "one, two, three" as opposed to by their root note position in the scale.
He's calling the Tonic #1, the Subdominant #2 and the Dominant #3. We would call these I, IV, V.
He uses them in his chord schematics...but doesn't use them to tie to the tunes (other than the chord schematics show the chords that appear in the tunes that follow). I would have at least put the numbers on the staff for the first couple of tunes in each key.