We should probably separate the group from your office from the group from Qatarliving, because of the number of people.
Also, my concern about D-Ring and the location of your office is the The Mall Roundabout. For those who will be coming from your side of D-Ring, we can always use "backyard routes" but for those who will need to cross the The Mall Roundabout at the proposed time, it will be a nightmare. Nobody will arrive at the right time.