There were the official chaplains - usually men of the cloth, from home - who were commissioned specifically as chaplains and show in the records as staff officers. I'm not sure how long most of these stuck it out with the troops.
There were also "unofficial" chaplains - enlisted men without the assigned post. As such they are without records of service as a chaplain and show as a private or corporal, as Braswell apparently does, but were identified by themselves and others as filling that role. This group of chaplains are often identified in letters (private and newspaper) and reminiscences.
Are you able to list the source of your information?