The British military system, wherein commissions were bought and aristocrats given preference, denied many men of ability roles they should have played.

From 1776 by David McCulough. Page 77.

Among those of lesser rank, an outstanding example was John Montresor, an officer of engineers whose years of service and experience would seem to make a mockery of the very idea that someone like Nathanael Greene could be a major general. Montresor, too, had served in the French and Indian War, in the Braddock campaign and at Wolfe’s siege of Quebec. In 1760, at age twenty-four, he had led a winter expedition overland from Quebec to New England, and at the war’s end worked on fortifications from Boston to Detroit to New York City, where he bought an island, Montresor’s Island, in the East River. He was resourceful, energetic, probably the best engineer in the British army, and with experience in America to equal any.

But it was also true that Howe and Clinton disliked one another and did not work well together, and that John Montresor, who was not an aristocrat, was still, at nearly forty, only a captain. If the desperate American need for leaders had thrust young men like Nathanael Greene into positions beyond their experience, the British military system, wherein commissions were bought and aristocrats given preference, denied many men of ability roles they should have played. Had Captain John Montresor been a major general, the outcome of the struggle might have been quite different.

A general observation: as a nation characterized by optimism, appreciation of the underdog, and high support for both redemption and second chances, one of America's saving graces over the decades and centuries has been its ability to elevate men and women of talent independent of their backgrounds and based largely on their abilities.  To a far greater degree than most societies.  It hasn't worked completely for everyone, but to a far greater degree than almost anywhere else.