AoS Ophidian Archway

Hey y'all!

I am puzzled by the rules of the Ophidian Archway, specifically by "Awaken Graven Carvings", which says the following:
1. If you have any hero near the Archway (3") you can use this ability
2. Point at an enemy model within 6" of the Archway
3. Roll a dice.
4a. If that roll is equal or greater than the enemy model's bravery, it is slain.
4b. If the dice roll is 1, roll another dice. Same as 4a, but for your hero.

So (as far as I know, I don't know much about Warhammer yet though, I am sure there are more) this is one of the two exceptions to the rule that the defender chooses the slain model from a unit, the other one being the Aleguzzler's "Stuff 'Em In Me Bag". No problem with that, I just noticed it.

Now my question: Isn't that kinda useless? I mean, even models with poor bravery have a 5 or so, don't they? Stormcast, Seraphon, Demons, Undead, and some others have Bravery 10, and bravery values of 8 or higher are not uncommon. Even with the -1 on Bravery caused by the other ability ("Sinister") if the enemy is very close (3") every unit with a bravery over 7 is pretty much immune. Even Savage Boarboys, Gors, or Skaven (Bravery 5) have a less than 50% chance of losing a single model at the hands of this ability.
First I thought it could be good with a Troglodon near ("Primeval Roar" gives -1 to Bravery within 8") but the Troglodon Warscroll states that it applies only in the Battleshock phase.
So yeah... I guess it is a small bonus for us (or other armies with good bravery), because we are not threatened at all by it, but... meh. Still sounds kinda useless to me. If it were two dice I'd say it would be more interesting.

So what is your opinion on this piece of scenery?

 

This is the way to do it, you bring down the bravery then snipe a hero

 

I think the Dread Saurian doesn't work either!
Its warscroll clearly says "if your opponent takes a battleshock test for a unit"
This is not a battleshock test.

 

Yeah, by itself, "Awaken Graven Carvings" is pretty much garbage.