Group rates are rarely cheaper than internet or discounted agents rates. They are generally a discount on the published rate.

Essentially Groups have to travel, so there's no real point in any airline heavily discounting for them.

Generally CX (and most airlines) won't take group bookings directly in countries other than their home port due to the larger work involved and you'll have to contact an agent with a 'Groups' department.

The best thing is to contact a Travel agent in the country of origin of the first flight.

For smaller groups just over the 9 limit, you might find it cheaper to book a couple of tickets, say for 6 and 6.