From Columns.
The First n dancers Peel Off to end in a Line of n, Step Ahead as necessary to form a Concentric Line of 2n and Bend The Line of 2n as the other dancers Extend (using Circulates) to form a compact formation, Trade, and Roll.
n Step(s) At A Time can be fractionalized into thirds.
This is the starting formation for each of the following:  
after 1 Step At A Time 
after 2 Steps At A Time 
after 3 Steps At A Time 
after 4 Steps At A Time 
2 Steps At A Time:

Cross n Step(s) At A Time [C3B]: First n dancers Trail Off instead of Peel Off.
This is the starting formation for each of the following:  
after Cross 1 Step At A Time 
after Cross 2 Steps At A Time 
after Cross 3 Steps At A Time 
after Cross 4 Steps At A Time 
Criss Cross n Step(s) At A Time [C4]:
First n dancers Trail Off, Step Ahead, and (Concentric) Bend The Line of
2n as others Extend to form a compact formation & Slither, Trade,
and Roll.