General Groves was advised, he explains (in Now It Can Be Told: The Story of the Manhattan Project), that he could improve his working relationship with the Los Alamos scientists if he appointed a committee to review their work:
[Dr. James B. Conant] pointed out that these people were accustomed to making their views known to similar committees appointed by their university administrations, and that our adoption of this system would meet with their approbation. A further advantage which we both recognized was that a review committee, with its fresh outlook, might be able to make a suggestion that would be eagerly seized upon, whereas if the same suggestion came from me, it might be regarded as interference.
Personally, I never found the idea of a committee particularly obnoxious so long as I recalled the opinion of a very wise and successful Chief of Engineers, General Jadwin. When some of his subordinates intimated to him that there was no need to appoint a board of consultants on the Mississippi River, since its members would have neither the knowledge nor the background in this field possessed by many officers of the Corps of Engineers, Jadwin replied: “I have no objection to committees as long as I appoint them.”
[…]
Out of the Review Committee’s work came one important technical contribution when Rose pointed out, in connection with the Thin Man, that the durability of the gun was quite immaterial to success, since it would be destroyed in the explosion anyway. Self-evident as this seemed once it was mentioned, it had not previously occurred to us. Now we could make drastic reductions in our estimates of the Thin Man’s size and weight. Because the gun-type bomb thus became militarily practical at an early date, work on it could go ahead on an orderly and not too hurried basis.