How did the Marquis de Lafayette and Baron von Steuben play similar roles in the American Revolution?

Both Marquis de Lafayette and Baron von Steuben, played the roles as Major General in The Revolutionary War.

Explanation:

Marquis de Lafayette (1757–1834) was a French general and political leader who enthusiastically supported the American Revolution. The Continental Congress appointed him as Major General in 1777, before France had officially entered into an alliance with the United States.  

Today, Lafayette's name is prominently memorialized in the U.S. capital, most notably in Lafayette Park, directly behind the White House—a clear indication of the indebtedness Americans felt to him after his valiant service to their cause. Lafayette played a critical role in the ultimate victory of the Revolutionary War, co-leading American forces in the successful siege of Lord Cornwallis' British armies at Yorktown.

Friedrich Wilhelm August Heinrich Ferdinand von Steuben, also referred to as Baron von Steuben, was a Prussian and later an American military officer. He served as Inspector General and a Major General of the Continental Army during the American Revolutionary War. He was one of the fathers of the Continental Army in teaching them the essentials of military drills, tactics, and discipline. He wrote Regulations for the Order and Discipline of the Troops of the United States, the book that served as the Army's drill manual for decades. He served as General George Washington's chief of staff in the final years of the war.