I got some more background on the transition of personnel -
The act that authorized the Space Force does not allow rank and file AF personnel to be transferred over for a year. Everyone who will be added to the Space Force this year will be done on a person-by-person basis. The AF can (and is) assigning people to work with the Space Force, but this is not the same as these people joining the Space Force, if that makes sense. Also, the Space Force has been barred from taking elements from the Navy and Army as I previously mentioned, but this actually has an expiration date and already the Army is looking for ways to begin shifting personnel and programs over to the new service when the transfer ban is lifted in a couple of years. The Army has always been enthusiastic about space, even when the Air Force was reluctant.
The fact that the Air Force wound up running the military's space segment was as much an accident of history as anything per-ordained; the Army artillery corp has long supported rocketry and the earliest successful American space efforts all came out of the Army's Huntsville operation. The next successful space program came from the Navy and the Air Force only got involved after that as a way to consolidate their control of all land-based ICBMs instead of the Army.