What newspaper accounts are you referring to? And when were they published? (62,63, 64, or 65?) You would not see much of it before the war, as newspapers were talking of the horrors of emancipation. If Cleburne was not unique, why was the Davis leadership not flooded with proposals to arm slaves throughout the whole war? His proposal was so secret, it was not commonly known of, till years after the war. The Southern leadership was prejudiced about arming armies/ranks of slaves and giving them equality, or they would not have seceded and fought the north to keep their rights to slaves.
Now, it is interesting in 1865 that Lieut. Robert Collins of Cleburne's Division wanted to command North Carolina "Confederate buck negroes. This seemed desperate circumstances, and were in for any port in a storm". Collins was interested in advancement on rank, feeling he deserved it, and this would have given him that advancement, if it were not for Sherman.