We dissected the units for about three hours before committing anything to paper. Here were our thoughts after that:
285 Swarm lord
196 30 Termagaunts (19 x Devourers)
210 Tervigon (Cluster spines, Electroshock Grubs)
162 9 Skyslashers
90 2 VenomThropes
150 3 Zoanthropes
130 5 GeneStealers+ Broodlord
130 5 GeneStealers+ Broodlord
165 3 x HiveGuard
120 3 x Biovores
Took a while to work this out. We moved units in and out of the matrix to see which ones would do the thing we most wanted them to do and when we would want it. Pretty torn over the Hive Tyrant vs. Hive Crone but we finally decided on the Hive Tyrant. That was an area we talked about a LONG time. The Psyker powers of the Hive Tyrant were a big selling point though. Tyranid Psyker powers are pretty awesome and the more chances you get to give out FnP or to pin the enemy, the better. Its marginal performance against multiple flyers will have to be offset by what it contributes in defense.
Effectively the way it works is that the Broodlords will infiltrate and pin units down (using The Horror). The Zoanthropes roll for a second power may also yield The Horror, though many of the powers would be very good, as they will be helping to provide Synapse and they can do a lot to protect the various broods around them if need be.
We wanted something to counter the Eldar shenanigans with their Serpent hulls, so we included a unit of Hive Guard to help us bring down one or two of those. The fact is, Hive Guard can really take on a LOT of things and provide first blood pretty well if given a chance. BS 3 isn't awesome but...
The Biovores are just a FANTASTIC tool. It's really amazingly worthwhile to take them. For one, it's a barrage, so yet another chance to pin the enemy (seeing a theme?). For two, for those who've read the rules, it can pump out an incredibly awesome and almost guaranteed blast of great power if it fails initially to do its duty. Talk about a fun unit. AP 4 is awesome against so many armies as well. Interesting tactics came to light while we discussed what a MISS would allows us to do and it was pretty fun to think about. You don't HAVE to ram the spores into anything. They can just form a fence when needed. They can also be used to slow enemy movement, cut off flyer movement and so on. It just has a lot of uses.
The Mawlocs function is fairly obvious: try to intentionally force the mishap so your weapon can go off twice, potentially killing any singular target you want. The important one preferably. Things like Riptides will care LESS, but they won't NOT care entirely! Against Markerlights, and other high value targets it will be immeasurably useful and if the enemy does not kill it, it gets to do it all again. If its not killed, it provides cover and forces the enemy to fire on it. If pinned the enemy may find that more difficult.
The Hive Tyrant makes the Tervigon outflank, and in effect, allows its babies to have done the same. Great for objective stealing and surprising the enemy flank as well as affecting their deployment. All kinds of plus's. The Swarmlord ensures its timely deployment and the mawloc come on in turn 2 (we hope) and keeps on coming. This effectively gives the army 5+ troops choices. the Swarmlord has an immense radius of Synapse, which will help in the round after reserves arrive since Synapse is not checked on units newly arriving from reserve.
All in all I was pretty pleased with the concept. Anti-horde control for zombi armies is well under control. MEQ armies will find the army more than a match in melee and the availability of dual chargers and fleet units will mitigate the effects of overwatch. The lack of AP 3 is a bit of a blind spot and MEQ will not wilt easily under the shooting, but of course they are Tyranids...
One thing we didn't explore as much yet because we want to see what happens, is whether it makes sense to do two units of Sky slashers instead of one. Not too sure about that part. I think testing will give us a good guess. he plans to give it a whirl tomorrow.