"fair play" deleted, why?

"Ah! my good friend, let this wild mountain air have fair play; let us with the desert's freedom joyously float convention and opinion—upstart usurpers!"  "Scenes Beyond the Western Border," Southern Literary Messenger  (August 1852): 508 

 In revision for the 1857 book version, "fair play" was deleted, thus:

"I am only in a mood; buoyant and bitter; tameless as the Arab coursing his native desert; free as yonder soaring eagle! it's this wild mountain air! Let us have a fling at the world,—the poor dollar-dealing sinners, cooped up in their great dens—"

Friend.—But you began by a fling at me—

"Only a love tap, Friend; my way of argument. Let us with the desert's freedom joyously flout convention and opinion—upstart usurpers!"  (Scenes and Adventures in the Army)

 Why delete "fair play"?  Uncomfortably close to, or evocative of, Ahab's language in Moby-Dick (1851)?

"Talk not to me of blasphemy, man; I'd strike the sun if it insulted me. For could the sun do that, then could I do the other; since there is ever a sort of fair play herein, jealousy presiding over all creations. But not my master, man, is even that fair play. Who's over me? Truth hath no confines."  (Moby-Dick, chapter 36)

 "'Avast!' cried Ahab; 'let's have fair play here, though we be the weaker side.'" 
(Moby-Dick, chapter 119)

silence, fearful, never so

 Herman Melville, Pierre, or The Ambiguities (1852):

"Pierre," said Isabel, "this silence is unnatural, is fearful. The forests are never so still."

 "Scenes Beyond the Western Border" in the Southern Literary Messenger Volume 19 (March 1853) page 157:

F.—"And what was there remarkable in my natural calmness?"

C.—"It was never so! There was a brooding desolation around that could penetrate a sleeping soul!—There is a re-action of extraordinary excitement,—such as ours of yesterday—that has a power over me which renders a profound silence awful—of all else, fearful! Silence! Then, every sentient of my soul has ears, in which air spirits supernaturally whisper distracting, sonorous thoughts :— in darkness, with long unrest, it verges madness..."

Note:  the line with "never so" disappears from this dialogue in Scenes and Adventures in the Army.  Also missing are the words awful and fearful ("fearful" in the revised version becomes "fearfully," thus:  "My watch is lonely and fearfully silent").