You should make the quest a bit more difficult, especially for mages who have geno...
Like, put some graveyards around, with monsters coming out from non-perm walls...
Also, can you make the monsters respawn very fast, if not, it's so easy to geno all from outside and then take your time to carry all the stuff at home. 8)
Another idea, you can have perm-walls outside so that monsters don't go out (trees are a good idea to prevent going inside

but inside you can put normal walls with a big zoo in the middle :o and some wall diggers (the X men).
Last idea to make it harder for mages: put some lice infections... mouses or rats by thousands, so that mages will not dare launch a geno attack (other warriors will kill them easily without even noticing

and last idea: lots of traps (there was none) some sumon traps, and some detroy items traps too. ;D
But once again, the most important point to me is that monsters never run short in that quest level (automatic respawn when 50% are killed).
herbert ^_^