Qy.: Are any of these tactical improvements by Xenophon himself?
C3.21.The "regiment" of a hundred men was divided into four "companies" of twenty-five, to each of these one company-captain and twenty-four men, viz.: twenty privates, two captains-of-ten, and two captains-of-five, the two captains of ten having also especial charge over the two remaining squads of five.

A condensed diagram may make the little manoeuvre clear.

An X represents one group of five plus its captain, either a captain-of-five or a captain-of-ten.

A C represents a company-captain.
First position--One long column.

All in single file.
Second position--Four columns.