TM, you wrote " At least three companies were raised in Richmond and did see service "in the trenches' before the war ended."
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Among the many writings of AA serving in the Confederate States Army the following excerpt from Wikipedia pretty much sums up the situation .... and it addresses the "Richmond companies".
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African Americans in the Confederate Army
http://en.wikipedia.org/wiki/Confederate_States_Army

"Nearly 40% of the Confederacy's population were unfree ... the work required to sustain the same society during war naturally fell disproportionately on black shoulders as well. By drawing so many white men into the army, indeed, the war multiplied the importance of the black work force."[10] Even Georgia's Governor Joseph E. Brown noted that "the country and the army are mainly dependent upon slave labor for support."[11] Slave labor was used in a wide variety of support roles, from infrastructure and mining, to teamster and medical roles such as hospital attendants and nurses.[12]

The idea of arming slaves for use as soldiers was speculated on from the onset of the war, but not seriously considered by Davis or others in his administration.[13] Though an acrimonious and controversial debate was raised by a letter from Patrick Cleburne[14] urging the Confederacy to raise black soldiers by offering emancipation, it wouldn't be until Robert E. Lee wrote the Confederate Congress urging them that the idea would take serious traction. On March 13, 1865, the Confederate Congress passed General Order 14, and President Davis signed the order into law. The order was issued March 23, but only a few African American companies were raised. Two companies were armed and drilled in the streets of Richmond, Virginia, shortly before the besieged southern capital fell. Several African American soldiers, free and enslaved, served with the Confederate Army during the war, but the Confederate Government failed to recognize their contributions until this late time.
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The last sentence is particularly telling in that it references SEVERAL African American "soldiers" ... Not several hundred, or several thousand, but simply several. It also mentions two (2)... NOT, the at least three companies that were 'armed and drilled' in the streets of Richmond shortly before the beseiged southern capital fell. Does that constitute action 'in the trenches'?

I guess our differences, if any, exist in the terminology of soldier. There is no doubt that thousands of impressed slaves labored in support roles for the Confederacy as did thousands of Blacks for the Union (men and women). Not as soldiers, but as cooks, teamsters, laborers, laundry workers, medic aides, etc. So please, can we speak the same language and not try to place square pegs into round holes?

Respectfully,
Art Thomas