The usable floor matters more than the starting picture
When you compare them, one thing becomes clear: every better sightline requires either extra width or an open center. A stationary formation still tells you little about whether it works while dancing. What matters is the outer boundary your couples reach during the movements you have already chosen. Arms, turns and side steps all count toward the space you need. An open spot in the starting picture is not yet a safe pathway.
Draw the usable floor as a rectangle and mark fixed obstacles: the stage edge, speakers, rows of tables and pillars. Then reserve access routes outside the dance positions; keep doors and marked escape routes completely clear. Only the remaining floor is available for the formation. As a simple drawing exercise, you can arrange twelve couples in different shapes without using this to infer a minimum floor area.
Look at each sketch from three viewpoints: the center of the audience and both side edges. This helps you spot obstructions that are invisible from above. The chosen performance format for your year group stays the same. If the formation only feels cramped because of oversized Waltz steps, the technique for shortening your Waltz step length can help; it does not make a genuinely too-small room safe.
