OK, I may as well get flamed for this one.
At the moment, the two MT members on the RC have other committments within the DSC on top of DD.
I believe it would be better to have someone who is soley responsible for DD matters and nothing else, as opposed to being Chairman/PR man/Treasurer/Window Cleaner and on the DD committee.
One person, who knows everything, knows everyone, is fully clued up on current events and happenings - and doesn't have to consult someone else who could be in Spain for 2 weeks.
That's the idea anyway.