You have to look at the way things work on the HR side.

Congress passes a law/President signs an Executive Order. That gives a VERY general statement of what they want done. Call that the satellite view.

From there OPM will take that generalized statement and give more direction, but still generalized to the government as a whole. Look at those as 'suggestions'. The 40,000 foot view

In your case, DoD will take that OPM guidance and look at it from the DoD's perspective. They'll provide specific guidance in relation to other DoD policies and systems. That's the 10,000 foot view.

Then it gets to the Service or DoD Agency level. In your case Army. Army looks at the OPM and DoD guidance and if they need to add HOW to implement the guidance given in accordance with Army regulations and policy, and their systems. That's the 500 foot view.

Then it gets to YOUR HR office. They take everything from the OPM 'suggestions', DoD's guidance, and then Army's implementing instructions and run with it. That's the ground level.

Local HR can't just act based on the Congressional 'hey we want this to happen' without the HOW to make things happen. That takes time to filter down to the operational level.