You can forget securing Du Pont installations in southern DE: at the time, virtually all Du Pont operations in DE were in/around Wilmington and just across the Delaware River at the Chambers Works in NJ. Thus, those jokers around Salisbury, MD were on a wild goose chase unless they were about to secure a bunch of chicken farms. You'd need to have troops going up the Kirkwood Highway from Newark toward Wilmington, with some splitting off toward New Castle on DE 9 and the New Castle/Penns Grove ferry to cover the places mentioned above.