Wow, looking good  

Have you considered alternate Scorpion armaments? I was thinking of Sonic Lances.

I have, in fact, considered a vibro-cannon based super heavy, but there are 2 way to do it:

Base it off of a pair of the revenant sonic lances (like you suggest), or basing it off of a single, larger gun that would later double as the tremor cannon for a phantom titan.

Going one route would use the scorpion chassis and a modified scorpion turret, while going the other route would use the cobra chassis.

The main reason I haven't moved forward with it yet is because it would involve having to get certain details of the turret to look identical to the existing scorpion or cobra parts, and I'm not confident that I can accomplish that. Also, given that it is a pretty strait forward weapon-swap conversion, I figure that it might not be worth doing (since all you have to do is cut off the pulsar and pin on a pair of the revenant sonic lance barrels).

If Otterman can work out casting my Revenant sonic lances and I can get enough of them to mess around with, I figure I'll mock up an EoV with sonic lances, to see how that looks. I'll post pictures of it if I'm not assamed of it.

I even have a name picked out already: Doom Caller. I'm not 100% satisfied with the name, but it will do for now.

I think that both would be worthwhile, especially as the Tremor cannon has a different profile to the Sonic Lances.

Thinking about other things you could mount on a EoV chassis:

Scorpion:

Twin Prism cannons
Twin large missile launchers (anti infantry/secondary AA?)
Twin large Starcannons (direct fire anti-infantry?)


Cobra:

Titan Fusion Lance (with less range?)
Warlock's Cobra with Psychic Lance?


I'm not sure how useful the Psychic Lance Cobra would be, but the very idea of it makes me want to try it....

Well, you know, sometimes discretion is the better part of valor.

Traditionally, the big guns of the eldar are the ones that the phantom was armed with. Anything that differs from that list will have a difficult time getting traction, I believe.

There's also the fact that just slapping a weapon system onto an EoV chassis doesn't always make a useful unit. The existing EoVs cover most of the roles that the units you describe would fill. I think that, instead of another big tank with one big gun, that maybe a big tank with a bunch of small guns would be something that the list currently lacks. That’s how the Tempest used to be, before it morphed into the Scorpion. Of course, then you get into the philosophical question of whether or not such an EoV would be appropriate for an Eldar list.

Personally, I'd like to see more AV tank units in the eldar list before more WE tanks are added. The main thing EoVs have going for them is the fact that no one will need to convert more than a few to have a full formation (compared to the number of AVs that would have to be converted to have the same number of points).

In any case, I think the best way of developing any new unit is to identify abilities that the current eldar units lack, then decide whether those are holes that ought to be filled (because those holes might be there intentionally to give the list flavor).

I believe that for an Eldar armored company list (the Yme Loc list) most of the roles typically filled by guardians and aspect warriors should be able to be filled by an AV unit instead (based on the assumption that such a list would represent a severe personnel shortage). To me, that means there need to be a few AVs that are assault oriented. My view of my sonic lance-based Rending Hammer grav tank is that it would be best used in a FF support role. I think there is also an opening for an entirely assault-oriented tank as well (i.e. a tank with only small arms and no shooting attack). Perhaps a token ranged attack would be acceptable, but nothing better than a 5+ to-hit and with a limited range.

Based on that criteria, what weapon system could we imagine (based on the existing Eldar weaponry in epic and 40k) would best fill that role and how would it look on the unit? Maybe a tank fitted with a series of weapons that act in the same way as mandi-blasters? Or perhaps one fitted with holwing banshee psyco-sonics? Maybe something as simple as scythes? In the end, whatever looks the coolest will be the best answer.

These are just my opinions, of course, so your mileage may vary.

Look here

I agree with all that you say. I was looking at an EoV chassis from an engineering/converting point of view, thinking about what could be fitted onto it rather than the use of such a thing.

The roles filled by the aspects are almost entirely assault-orientated, providing lots of decent FF attacks and a few (often MW) CC attacks. Could any of these roles be filled by Falcons?

Bearing in mind that an assault is approximating a full 40K battle, which weapons could be used for a new AV? Shuriken cannons, Bright lances, Scatter lasers, Starcannons and Missile launchers come to mind (some of which are available as FW waveserpent turrets - did these ever get epic stats?). We could also include things like the heavy weapons platform armaments - D-cannons, Vibro cannons and Shadow weavers.

I could see a formation of Falcons with twin D-cannon/Shadow weaver turrets, with a pair of Rending Hammers added on as making a good assaulting formation.

Did you have the Rending Hammers in mind to field as their own formation or as an upgrade/addon to another formation?