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Librarian-NullZone/Might of the Ancients-100
Tactical Squad-Melta/Combimelta/Powerfist/Missile/Heavy Bolter Razorback-250
5 man Scout Squad-Combimelta/4xBP+CS-85
2 x Typhoon Speeder-180
2x Predator Annihilator-330
This leaves me 225 points to spend. I have 5 Assault Terminators which are pretty good and scary. I also have a bunch more marines who could be made into a third tactical squad or a Sternguard squad. I'm not sure whether the super-combi-bolters are worth losing scoring status.
I plan on using the Predators to tackle Heavy armour, AV13+ and thats why they're proper Tri-las ones. The Autocannon is good but not for what I want to use the tank for, because it can't pen AV13 (I play lots of Guard and Vindicator marines). I know Fast Melta is usually the go to weapon for this, but I prefer to sit back at range instead of gambling on suicide units. If it comes to it, it can still tear transports apart along with the Dread and the Typhoons.
The Typhoons should get some side armour shots against a rushing enemy, or can sit behind the Preds for a cover save and fire away at 48"
The Scouts can give a nasty surprise to any unit <12" from the table edge and are very cheep. Good for objective grabbing late game too.
Librarian is in the Razorback with a combat squad. I kept it just Heavy Bolters so as not to draw too much attention to itself! He Null Zones any scary unit or can shred a vehicle or infantry unit with MotA.
That's about all. Any tips on where to spend that 225? And advice on what could be made better?
It's not bad overall - you've certainly got the bases covered. I'd suggest taking either your assault terminators, or a third tactical squad. There's really good arguments for both units.
A note about the predators though: I can understand your reasoning for taking tri-las preds, but the 2 you have come to 330 points...whereas you could get 3 AC/LC predators for just 30 points extra. You'd have just as many lascannons on the table, but with 3 extra autocannons to back them up as well. All things considered, I submit that as a pretty good deal.
My other suggestion is that you run a team of sniper scouts with Torias Tellion with your extra points - he's an incredibly useful fellow to have in your army, with all of his special rules.
Good point on the Predators! Having the extra tank chassis around would be a big benefit too. If/when I get another Predator that's a really good idea. It'd be pretty tricky for an opponent to hide from all 3, or to destroy all 3 for that matter.
Scouts with Telion has worked for me before, he managed to snipe a powerfist sergeant but then fluffed his rolls for the rest of the game. My outflanking guys have got a lot of points for me too, taking out of the way objectives/hitting vulnerable flanks so I'll keep them in the list for now.
The Terminators would be a decent counter assault unit, running behind my Rhinos or chilling out by the tanks. They also attract huge volumes of fire and often take a whole turn of enemy shooting before going down. But another Tactical squad would give me 4 Troops choices and 7 scoring units. I could send two squads to capture objectives rather than just the one. Tricky choice to make.
I'm with watchwood on the third pred. more ranged firepower for a small increase in points and having a third tank on the field is very good.
Now I'm not to keen on using assault termies as a counterassault unit. If you feel you need a counterassault unit in your list, I'd go for a unit of assault marines or even vanguard with a transport.
Don't dissmiss the sternguard though. Even if they don't have scoring status, they bring alot to your list. With the special ammo they can take on any type of infantry and even if they get stuck in CC, they are no pushovers.
I would switch out that Lib and add a chaplian and pair him up with the terms. I would do 3 claws and 2 hammers, thats a mean mix being the re-rolled hits.