If you want to know "the best place" for a state-level emergency management agency, it is directly reporting to the governor.
The good news, in my opinion, is that Oregon's Office of Emergency Management is moving out of the National Guard and being placed directly under the Governor.
On July 1, 2022, Oregon will have a Department of Emergency Management, HB 2927 . The same bill also directs the state fire marshal’s office to develop a plan to move out of state police; they too would be a standalone agency. The bill also beefs up the state’s homeland security councils.
Here is Gov. Brown's current Resilience Page.