Only tarun DK's have any possibility for multiboxes cause of the increased mellee range.

Like was suggested its possible to do a mellee group by haveing a tiny leader and moving to the right or left of the mob and that will bring the tarun dk followers in range.

I havn't tried it but it seems possible.

If you think you can control 5-10 mellee seperatly, well forget it. I suggest no more then one mellee under normal circumstances.