You have to TRY to get 30th place. If you just play 10 games as best as you can, you won't ever get 30th with this few people.
Also, I had trouble even completing 5 games since there were never any opponents late at night, when I actually had time to play Alteil. Also, luck's a ****. One of the high-ranking duelers that I went up against had 2 Return Grimiores, 3 copies of just about all his units, and I lost because I had no good endgame cards and I only had two copies of the key unit in my strategy. Fun stuff. I was pretty satisfied with the strategy I came up with, otherwise. It was pretty interesting having to stare at all these single or double copies of cards and scrap together some sort of workable strategy from it, at the very least. (I still regret entering in it though, since I never even got my 50 gran, much less place in the tournament, despite my repeated attempts to play.)
Also that 10 turn requirement on the 5 games should be shortened a little, since it's possible to just trash someone in the first 9 turns and then they quit the match. I wasn't keeping track of the turn numbers, but something like that happened in one of my games.