Ichor Injectors tilt the balance quite a bit.
If fighting a Shooty wraithknight, 2 talos (that makes it into combat, that is the tricky part) should kill the wraithknight. 1 can alone if a bit lucky.
Each have 4 attacks.
Talos hits on 3's, knight on 4's
Each wound on 2's
talos gets a 5+ feel no pain save.
So does the knight EXCEPT when you roll that wonderful "6" to wound. Then you do 1-3 wounds with no save of any kind whatsoever.
So knight swings first, hits twice, wounds twice, you save one if lucky. You still live even if you dont.
Talos hits 3 times, wounds 3 times and could kill it if one of those wounds is a "6"
So two talos should be able to kill it with no difficulty.
Against a HTH wraithknight... you make it there alive, but die ever so quickly after that. It would take a full corpsethief to kill one.
700+ points to kill a 295 point model.
Never fistfight with ugly people. They have nothing to lose.