Moroni took command of the city of Mulek then in turn gave it unto Lehi for both commanders were to each other as counter parts.
Lehi was one of his most trusted and efficient lieutenants. It was the same Lehi who was with Moroni in the Battle of Riplah and also he whom Moroni had made Chief Captain of the Nephite forces at the City of Noah. (Alma 49:17)
Lehi was a man like Moroni and they rejoiced in each others safetly. They were beloved by each other and also beloved by all the people of Nephi. Their love for the Lord was expressed in the greatest degree by the service they rendered to their fellow men. They loved liberty, the land in which they lived and their wives and children.
External trials such as the Nephites endured can sometimes point to internal needs.
Hugh Nibley said, "So it was a blessing to the Nephites after all to have the Lamanites on their doorstep to stir them up to remembrance - Happy is the man whom God correct-eth." No matter how wicked and ferocious and depraved the Lamanites might be, (and they were that) no matter by how much they outnumbered the Nephites, darkly closing in on all sides, no matter how insidiously they spied and intrigued and infiltrated and hatched their diabolical plots and breathed their bloody threats and pushed their formidable preparations for all out war, they were not the Nephite's problem. They were merely kept there to remind the Nephites of their real problem, which was to walk uprightly before the Lord.
From these dangerous circumstances we are introduced to the Stripling warriors. The stripling warriors were Lamanites by birth; the children of those converted by the missionary Ammon who had buried their weapons of war and taken an oath not to fight for their protection. These Lamanite converts were invited to live with the Nephites. These converts had many sons who had not taken the oath and they were willing to help the Nephites.
Helaman is the eldest son of Alma - keeper of sacred records, high priest and military leader. He is perhaps best known for his tender command of these young warriors.
Helaman is shown to be an adept spiritual and military leader like Moroni. He boldly declared his faith, led a large army, fought for the liberties of the people and used strategy to reclaim Nephite lands and cities - preferably without the shedding of blood.