When you push a 3 member  " 3 picks " Rhythm Pick across the 6 strings of a Guitar.

   Each of the 3 picks, picks 6 strings on the Guitar. With each of the 3 picks picking 6 strings, this

   equals 18 individual Beats that are picked with 3 picks, picking 6 strings on the Guitar.

    3 times 6 equals 18.  With 3 picks you have 18 beats,  The Primary Belts of Beats use only 10

   individual Beats to make these Belt of Beats. If you only use 10 Beats when you have 18 beats, that means you have 8 Beats left over. The Secondary Belt of Beats use only 12 individual Beats to make these Belts of Beats. If you use 12 Beats to pick a Belt and you have 18 beats then you have 6 beats left over. With 3 picks, picking 6 strings giving you 18 beats there is plenty of Beats to pick these 10 Beat Belt and 12 Beats Belts. This is why all this is possible with 3 picks.