7th edition Eldar Mathshammer - Which multi shot heavy weapon to use and when?

So the new codex comes out and there have been very few changes to the heavy weapons in the Eldar codex.  Or have there?

In the last edition, the Scatter Laser was king.  With laser lock the others rarely got a look in. However times change, laser lock has been resigned to the bin of history and so everyone gets to have another chance.  In this article I will compare the Scatter Laser (SL) with both the Shuriken Cannon (ShC) and the Starcannon (StC).

The reason for this article is that I read somewhere on a popular blog that there is no point in using starcannons because they are flat our inferior to scatter lasers still.  I am not so sure that is the case, so lets run the numbers shall we?  I will take several basic statlines and compare the damage each weapon does against them.  We will use GEQ, MEQ and finally TEQs.

GEQ - Toughness 3 5+ saves
SL 4 shots, hit on 3s, wound on 2s, saves on 5s.   1.49 kills
ShC 3 shots, hit on 3s, wound on 2s, no saves (bladestorm irrelevant here) 1.66 kills
StC 2 shots, hit on 2s, wound on 2s, no saves. 1.11 kills.

In a surprise to me at least, the Shuiken Cannon comes out on top here.  Saving one in three wounds really hurts the Scatter lasers damage output.  It will likely only get worse from here on out for the previous king.

MEQ - T4 3+ saves
SL 4 shots, hit on 3s, wound on 2s, saves on 3s. 0.73 kills
ShC 3 shots, hit on 3s, wound on 2s, saves on 3s (bladestorm kicks in)  0.64 kills
StC 2 shots, hit on 2s, wound on 2s, no saves.  1.11 kills

So unless my maths is wrong, the Starcannon is the best performer here.  Against the most common, popular models in the game.  Now obviously cover saves do matter, but that will only reduce the Starcannon to 0.74, still leaving it the strongest performer here.

TEQ - T4 2+/5++
SL 4 shots, hit on 3s, wound on 2s, saves on 2s.  0.37 kills
ShC 3 shots, hit on 3s, wound on 2s, saves on 2s (bladestorm kicks in)  0.46 kills
StC 2 shots, hit on 2s, wound on 2s, saves on 5++.  0.74 kills

As the armour improves, the Scatter laser really loses out. The only time the scatter laser may be the optimal weapon is against a target with an armour save of 6+ or worse.  Outside of orks, I don't think there are a great many of those around.

7th Edition Eldar - Combining lethal formations

One particular combination I have found in the new Eldar codex is just plain lethal.

You take an Aspect host.  This can be any three aspect warrior units and they all gain bonus ws or bs.  This is really strong.

You can also take an Engines of Vaul formation, of three Falcons.

Combine these two together and you can create this;

6 Fire Dragons, inc exarch
6 Fire Dragons, inc exarch
6 Fire Dragons, inc exarch

3 Falcons

Put them together and you get a unit that deep strikes without scattering, delivering a massive amount of melta guns with pin point accuracy.  Not many players would thank you for this.