Final answer:
The Army Commanding General's power to sub-delegate deviation authority depends on current military regulations, which are not specified in the given information. Historical acts provide context but do not directly answer the delegation question.
Step-by-step explanation:
An Army Commanding General in a command position, not lower than installation commander, may have the authority to delegate certain powers. However, the extent of this sub-delegation and to whom it may be assigned depends on the regulations, directives, and laws governing military command authority and structure.
It is important to note, as per the information given, that delegation of authority within the military context needs to be aligned with proper channels and hierarchies. According to historical acts such as the one mentioned that discusses the division of unreconstructed states into military districts, federal military commanders had specific responsibilities and powers. These past examples illustrate the delegation of authority but do not directly answer the question of who a Commanding General can further sub-delegate deviation authority to, which would require a specific reference to current military regulations or a direct directive that outlines such delegation.