So we finally have a new codex that has a dedicated option for anti flyer defense other than another flyer. That's right - I'm talking about the new Chaos Space Marines (CSM) Havocs. Havocs are the equivalent of Space Marine (SM) Devastators and Space Wolf (SW) Long Fangs. Flakk missiles (S7) allow a Havoc armed with a missile launcher to use their normal BS when targeting a zooming enemy flyer or flying monstrous creature (FMC). A good question that has been posed is are they worth their points? Versus say a Necron army with a lot of flyers most likely the Havocs will draw a lot of enemy fire starting the second turn. One suggestion is to arm Havocs with either lascannons and/or autocannons. The first major issue I see with this option is that Havocs armed as such must snap shoot so they are drastically less reliable. I have not had a chance to study the new codex in depth to see if it's possible to reliably boost Havocs such that they can reroll missed hits (for example, the psychic lore Divination) so for now I'll assume it's not the case - feel free to correct me if I'm wrong. If it is possible the cost in points to do so should be carefully weighed.
So let's take a quick look at some comparisons to see statistically which build will produce better results versus enemy flyers. We will look at both versus AV11 and AV12. The first is five Havocs armed with four flakk missile launchers versus four autocannons - both shooting at AV11 (because it is more common).
• Flakk Missile Launcher - 4 shots * 2/3 = 3 hits (rounding up)
To glance - each hit has 50 percent chance, 2 glances (rounding up again)
To penetrate - each hit has 33 percent chance, 1 penetration
• Autocannon - 8 shots * 1/6 = 1 hit
I'll stop right here with the first comparison as it is obvious to me the flakk missile launcher is the better choice due to sky fire. Even if the missed shots can be rerolled the results are not as good so for this particular case quality is better than quantity. If we switch out the autocannons for lascannons the odds to hit go down even more drastically and you've lost the saved points in lieu of autocannons - the only real advantage being is if you do hit then you have a better chance to penetrate.
If you run two five man squads of Havocs armed with flakk missile launchers your odds of dropping one enemy flyer (again AV11) due to glances is as follows:
• 8 shots -> 6 six hits (rounding up) -> 3 glances * 2/3 (assume the flyer evades) = 2 glances
So by the odds it will require two turns to drop one enemy flyer (AV11) not taking into account the effects of any penetrating hits. Is it worth the cost in points? A five man Havoc squad armed as such costs 175 points which comes to a grand total of 350 points for two squads... 360 points total if you should also upgrade them with the option for Veterans of the Long War (that is, Ld10). That seems quite reasonable to me. I want many long ranged high strength (S7+) to shoot enemy flyers.
As I pointed out above it is very important to consider how an opponent will react whose running a flyer heavy army... The basic assumption being that starting on the second turn the Havocs will begin to draw a lot of enemy fire in return. Five man Havoc squads are fairly fragile due to the low model count so they should be deployed in cover with excellent lanes of fire across as much of the board as possible.
I want to design a CSM army with lots of long range firepower to force opponents to have a difficult decision which of my units they should target. This strategy will add some resilience to your Havocs should decide to field them.