Blood Slaughterer Impalers (or: Fishing for Daemon Princes)

As I understand it, this is a bit of an old question, but with IA 13 marginally tweaking the rules for the Impaler (but not clarifying the issue), I figured it was worth running it past you guys.

So, the Blood Slaughterer is the Khornate big-brother of the Maulerfiend, takable by all flavours of Chaos.  For a pittance you can swap out one of it's DCCW for an Impaler, a harpoon-style gun that operates in a similar manner to the Blood Angle Magna-Grapple, but with some curious wording.  As the model has an utterly abysmal BS, it has a line of text that simply states that "Using the Impaler counts as a shooting attack, which hits on a 4+".  Furthermore, should said shot Pen/Unsaved Wound, the Blood Slaughterer tries to reel it's target in, moving the target 2d6" in a straight line towards it (or until it runs into something else), and if the two meet, it's assault time!  It does have a clause specifically barring it from moving Super-heavy Vehicles and Gargantuan Creatures, but it makes no reference to zooming fliers or flying monstrous creatures.

I find it rather odd how many books this Daemon Engine has gone through since Fliers have become a thing without this question being resolved in at least one of the texts.  I also find the concept of a pack of Blood Slaughterers going all Scorpion on Fateweaver and forcing him down to play, frankly, hilarious.

I can certainly see a fluff angle for supporting this approach to the Impaler, but the crunch side remains ambiguous.  It really feels like there should be some clause in there along the lines of "a Swooping FMC counts as having been grounded, and a Zooming Flier counts as having entered Hover mode if it is capable", but this thread wouldn't be started if that were the case.

So, this arguably leaves us with a weapon that has roughly two thirds of its rules written and presented to us.  What do you guys think on the subject?

Well, I assume snapfire to catch the bugger out of the air, then reel the sucker in, ignoring grounding. Why not? With the insane number of varying rules out, I can't see how it would break the game. Especially when you tell your opponent what the thing can do, and the slaughterer is a hunk of irradiated metal goo 5 seconds later from all the shoots

wait... just had a flash of potential glory.
doesn't it say under zooming flyers that if they move less than 18" they crash? so if you pulled it, would it autocrash...?

I'd have to check, but I think that's under the purview of the movement phase. I like the imagery, though.

Doesn't this follow the standard formula? Set modifiers are before snap shots unless there is an exception listed in the rule (markerlights for example); thus requiring a 6 to hit?

The rub is that, as worded, it doesn't shoot using it's BS. It is a shooting attack that hits on 4+. And as no other gun does this, we have no rules precedence for how this interacts with snap shots. Some interpretations I've seen include "well, it can't snapshot and thus can't shoot fliers" to "it always hits on a 4+, so each Impaler in the pack has a 50/50 chance of connecting, even when shooting a flier". Conversely, charging a pack of Blood Slaughterers could be a scary concept, because if you charge them, and they use the Impaler on overwatch to pull you all the way in, they'll count as having gotten the charge off.

What a (bloody) mess of rules this daemon engine is.