The 15-20% reduction includes the VSP and other attrition and cuts (like contractors) that have already happened. They have said the rest will happen in 30-60 days across the entire org. This is happening in one fell swoop when it does. Good news is lots of engines are flying again.
The best case scenario for military is flatlined budget going forward. That could get cut with the election and other politics coming, good chance of it.