zyrinia is 100% right. you will get shot to pieces against any other army. youre much safer in anything that can transport, but one minor change would be breaking up the wyches into Two venoms instead of a Raider. the Venoms can take 12 poison shots with two splinter Cannons, you'll clean up a lot of infantry that way. flank your warriors with them and you'll shoot so many poisoned shots at your enemy they'll go blind, then run over them and drop the Wracks on your opponents, they'll have FNP and then Furious Charge, the enemy won't stand a chance after that.
+ Flesh Gauntlet (anti HQ weapon from GOD)
+ shattershard (if you can fit it)
10 warriors, splinter cannon
Raider, DL, splinter racks
5 wyches, Venom, 2 Splinter Cannons
5 Wyches, Venom, 2 spinter Cannons
i wouldnt spend points on their Hekatrix, but that's just me, you could add the agonizer/etc and be successful, you'll have 2 Dark Lances, 5 6 shot Splinter Cannons. 30 shots in 600pts, never had a chance.