on warriors svything talons are the same cost as fleshborers, and a better bet as you won't be using borers if you have a deathspitter. If you are dead set on keeping them shooty - not a bad line - then you could give them two weapons the same as that will make them twin-linked - however most nid players with shooty warriors use a gun and scything talons - you never know they might make it into combat.
As a tip put a second set of twin linked devourers on the hive tyrant and give him a set of wings and your opponent will cower in fear - a very effecitve machine gun with 12 attacks with rerollable hits and wounds - very nasty.
Other than that a good solid list, not sure about the biovores - never used myself- but they are known to be extreamly effective against Chaos Khorn armies (they must charge the nearest enemy unit - drop spore mines into thier ranks and they have to charge the mines - funny
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