you can try, but i wouldnt suggest it...
Usually with 2-3 shaman controlling a tourny of only players we "know" arent gonna quit, or go AFK for a week, we can pull off a tourny of 20-24 people.
With 1-2 shaman, the past.... 4 tournys have fallen apart (i wasnt involved in them)
It would be really hard for you to get clan mates to join it also, because the people who wouldnt leave a tourny, are getting sick of the dozens of people who do leave, so the tourny cant finish. And quite frankly, as you can tell by the ...failed... pub/peon tourny, which failed pretty hard and fast, public players are very hard to organize.