At the bottom of the contract food chain is an army-for-hire of truckers, backhoe operators and tree-trimmers, most four, five or more tiers removed from the Federal Emergency Management Agency, the Army Corps of Engineers and the agencies\' money. Tiering worries small businesses even when there are no disasters involved, said John Chichester, who heads the Procurement Technical Assistance Center at Detroit \'s Wayne State University . \"The subcontractor -- they\'re generally picking up the scraps,\" said Chichester , whose center advises small businesses on how to win government contracts.