Trim Stab,
The A400M was designed to have a Para Wedge system capable of double the amount of stores the Herc could drop and we insisted on a flat floor between the rollers so that Store preceeding men systems could be dropped over the ramp.
The point is that men exiting the paradoors will have their canopies damaged if the ramp is also open.
However, back to the thread subject. One reason given by Airbus for the prop rotation was to provide an airflow that would reduce the 'Crossover' risk to Sim stick paratroops. Having seen the difference made to the airflow and parachutists crossover by the change of props on the C-130J. I remain sceptical of Airbus's claims.