A document processing arrangement transporting sheets at a prescribed nominal speed along a track, terminated by sort-pockets, each with an associated diverter plus a guide assembly for guiding and driving a so diverted sheet into its pocket, the guide comprising an inject roll to accelerate the sheet, plus an arm assembly coupled to rotate with the roll and including an arm for guiding a so injected sheet toward its position in the pocket stack; this roll and arm assembly being arranged to rotate the arm away from its stack each time a sheet is entering, and also to be spring-driven to return the arm toward its stack.