Recently, DJT has been attacking the Cheif of Staff Milley.
We know that Trump publicly attacked Jeff Sessions while Q+ (Trump) "Thank you for your service to our Country, Mr. Jeff Sessions!Your SACRIFICEs will never be forgotten. Q+"
We know optics are important. It would not look good if a publicly pro Trump general takes control.
The Chief of Staff does not have operational authority and command over the military, The position is an advisory position to the POTUS, SoD, and HHS.
What you are suggesting by the optics is hypothetical and impossible to determine at the present time.