However, the record is replete with enlisted soldiers who were discharged for less serious disabilities, not involving amputation, being later conscripted or, in some cases, allowed to voluntarily reenlist.
Your point about the dearth of records of reserve, home guard and militia units is one of the great stumbling blocks to Civil War research, particularly in the Trans-Mississippi Department. On this side of the river, only Texas has substantial surviving records of those units; probably because those units submitted their rolls to the State adjutant-general, and, since, the capital of Texas was never captured, there was no wholesale loss of records.