Chertoff impresses me as very smart especially in his currency with smart, sophisticated approaches to problems. We have previously had a lot of expensive low tech solutions that I found frustrating.
Chertoff is smart, OK. But what you need here is a lot of low tech moving of people out and supplies in. You need an operations manager that is used to managing large number of people.
Brown is a lawyer, political friend of a friend type appointee. Has no qualifications.
Lokey is a search and rescue type. But probably more trained on earthquake disasters than flooding.