This manipulation was helpful before the change of secondary positions qualifying for the mandatory required draft positions when putting a team together in the draft center.
One example is in a Progressive League where I took over a team in the We Aren't Dead Yet Progressive League, WADY. The Los Angeles Platypi.
I believe for the 1973 season I had 4 players who had a fielding grade for 3B, but none that had 3B as their primary position.
At that time the draft center would not allow that team to be entered, because there was no Third Baseman.
Joe Torre had been my starting Third Baseman for the 1972 season, but for 1973 although he qualified at 3B, his primary position was 1B.
With the knowledge of this manipulation I could enter the team by Having any player fill the 3B slot.
1973 Joe Torre
St. Louis Cardinals
1973 Tito Fuentes
San Francisco Giants
1973 Hal McRae
Kansas City Royals
1973 Gene Alley