If there were 6 marchers in line and ⅚ of the marches were out of step then 5 would be out of step; only one would be in step.
Consider all the marchers in lines or rows of 6 marchers per line/row.
That means we'd have 6, 12, 18, 24, etc. marchers; in other words, some multiple of 6.
There would be only one marcher in each row in step.
Example: 42 marchers:
❌✔️❌❌❌❌
❌❌❌✔️❌❌
❌❌✔️❌❌❌
❌❌❌❌✔️❌
❌✔️❌❌❌❌
❌❌❌❌❌✔️
✔️❌❌❌❌❌
The checked (✔️) 6 marchers are in step; all others (35) are out of step.