What type of game are you playing? It looks like this might be for a city fight game, if it is, then go for it with this list. If it's for a normal game then here are a couple things that I'd change-
Your army is fast, which is good for nids, but nids have issues with vehicles, especially those cheap AP4 tornado speeders, and you'll have even more issues with those because of your lack of shooting. Your zoan's are nice, but remember that you still have to roll to hit with them, which means that on average, only 1 will hit per turn. If you can, add some more guns.
I'm not sure the walking tyrant will do so well. He'll take 4 turns just to get to the enemy. I think you'd be better off making him shooty by swapping warp blast for ext. carapace, and giving him some guns: either devourers with the +1
STR adrenal glands, or even a barbed strangler &
VC loadout for vehicle hunting. If you change the tyrant to a shooty version then you won't need the guard as much as you can move the big guy from cover to cover, shooting all the while.
Changing one of those elite fexes to a 2x twin linked devourer fex would also help vs shooting.
Definately, definately give the stealers extended carapace. +1
Init on the flying tyrant might also be good. Giving him
init 6 will let him strike before most opposing characters.
Don't worry about flesh hooks on the hormagaunts, the +1
Init is nice, but even that isn't really necessary. Just remember that your gaunts are there to tie things up and stop the enemy from shooting just long enough for your stealers, tyrants, and fex's to get into
CC. If your gaunts even survive the battle then it's a bonus. Besides, the hive will just make more of 'em
.
Watch your synapse range and don't be too aggressive with your flying tyrant. He needs to stay alive long enough for your other tyrant and zoans to move into synapse range of your fast
CC elements.
SteveW
