The second rhythm is very nicely syncopated! You virtually divide your ukulele into 1 string for "bass" with thumb, and 3 strings for the chord. Those of us who pick just with thumb, index, and middle (and no ring) finger may divide the instrument into 2 strings for bass with alternating thumb, and 2 strings for the "chord". Of course the alternating bass works great especially on low G ukulele. Thanks for the inspiration!