Ooh, three groups of twelve instead of four of nine? That's going to be BRUTAL!
I'm amenable to changing my mind on this, but in my thinking there are the following options:
1. Three groups of twelve for semi-finals, 9 stories in the final.
2. Four groups of nine, 12 stories in the finals
3. Four groups of nine, 8 stories in the finals.
Option 3 seems has been used in past contests, but I don't like it - I feel it unfair to have a 2-winner bottleneck, because if the top 3 stories end up in the same semi (and I use a randomiser to sort them,
not any sort of seeding, so this is entirely possible), story #3 is screwed.
Option 2 seems to me to make the semis easier, but the finals even harder as all the favourites will clash.
Option 1 makes the choices in the semis harder, but it also makes people have to make fewer choices overall. It also makes the grouping easiest - each group will send 1 story (randomly chosen) to each semi.
Still, if there is general preference to option 2 over option 1, I'm willing to do that instead.