Welcome to the forum.
Roy has covered a lot of points I would have raised about this list, so I'll just add some areas which he didn't mention, and elaborate on a few points that he made.
The list is reasonably solid, but the sole Guardian squad on foot is vulnerable. You don't have an assault unit to protect it (Striking Scorpions are good for this in my experience), and Guardian Defender squads work best when fielded in pairs, since the firepower from two Scatter Lasers is more impressive than one, and they can support each other. At 1250 points, you may get away with only taking one squad, due to the fire support from the War Walkers, but certain strategies, such as the hammer and anvil, will not be viable with this mixed list, due to the fragile nature of the infantry component.
The mechanised wing is sound, but your Wave Serpents need Spirit Stones not Star Engines. You cannot afford for crew stunned results to fragment or slow down your attack, as this hands the initiative to your opponent. You may also wish to consider taking EMLs or Brightlances on the Wave Serpents for your anti-tank, since they are more accurate than the War Walkers (see later comments).
I agree with Roy about the Farseer. On his/her own on a Jetbike, the Farseer is likely to become a bullet magnet. I strongly suggest that you dispense with the Jetbikes, and attach the Farseer to the Howling Banshees or Dire Avengers.
The Warp Spider Exarch needs to be armed with the Exarch Deathspinner in my experience. They are primarily an anti-infantry unit, but they can also be used against vehicles with weak rear armour, or low AV in general. Either way, mass firepower is their strength, so I suggest playing to this regarding the weapon choice for your Exarch. The unit is also too small to get involved in assaults in my view, so you could drop Withdraw.
The best way to arm War Walkers in my view is to give all of them Scatter Lasers. This gives you excellent anti-infantry and light vehicle fire support. If you plan to outflank them, then Shuriken Cannons are an option too, as Roy indicated, but outflanking them in this list would leave your Guardians too isolated in my opinion, unless you're facing a gun line which is not going to advance towards you at any stage.
I understand that you're taking War Walkers with EMLs to give you some anti-tank, but without a Farseer with Guide nearby they are simply not accurate enough in my opinion, and they are not all that cheap, which is why I feel the Wave Serpents would be a better place to mount your anti-tank weapons in this list. Regardless of your weapon choice, you don't need the Spirit Stones (see the vehicle squadron rules to discover why
).
As far as your questions are concerned:
- Is the HB unit better then taking a Scorpions unit in terms of general utility?
They are both very good, and are surprisingly similar in effectiveness against quite a wide variety of units, although Howling Banshees have the edge against TEQs and MEQs (although only slightly in the case of the latter, assuming the Striking Scorpion Exarch takes the Scorpion's Claw), while Striking Scorpions have an edge against GEQs, particularly larger units. For a full discussion on these units, I recommend that you look
here, but please don't post in the thread, as it's old.
- I'm taking 3 War Walkers since I already have one from the BF box, but is this viable instead of taking 2 Fire Prisms? Consider the point cost, the actual cost, and the utility of having 6 EMLs within a 1250 pt army.
Both War Walkers and Fire Prisms are at their best against infantry in my view. EMLs are also something of a niche weapon against vehicles, specialising in dealing with AV12 (anything lower can be handled by mass Scatter Laser and Shuriken Cannon fire, anything higher is better dealt with by Brightlances, Fire Dragons, Wraithguard, or Warlocks). I see no problem with taking War Walkers instead of Fire Prisms, but if you're looking for anti-tank fire support from either of these, you're not playing to their strengths in my opinion.
-Are the Warp Spiders the best general fast attack unit out there for the point cost?
There are no general fast attack units in the Eldar list per se, but Warp Spiders are the most effective of the fast attack Aspects against the widest range of units in my view.
Overall, the list should perform quite well at the 1250 point level, but you will have to be careful with those Guardians, and you may wish to revise which units will be providing your anti-tank fire support. When it comes to expanding, you will, in my experience, have to bolster that infantry section though.
I hope that helps.
