The U.S. practices the “Whole Community” concept and calls upon Defense Support

The U.S. practices the “Whole Community” concept and calls upon Defense Support to Civil Authorities (DSCA) when necessary. Is the U.S. approach too complex? If so, what are your suggestions to enhance effectiveness? 
Sources: 
Article: A Whole Community Approach to Emergency Management (see attachment) 
https://www.gao.gov/products/gao-15-686t