Perhaps.

Or what about something similar to the Super 14 they have in rugby.

4 to 6 of the best provincial/franchise sides from South Africa, Australia and New Zealand. The Super 14 competition really gives you an idea on the "bench strength" of the Springboks, All Blacks and Wallabies. AND it gives the fringe players the international exposure they need.

Not sure about the logistics though.

Similarly, SA could help Zim too...