In both cases yes - but the hunter formation would be 450 points. But is it worth it? Against air assaults it would cover your army if deployed over a diameter of 90cm, less if they are FF assaulters (80cm) and against shooting attacks its 60cm vs 30cm and 30cm vs 45cm. Of course el hunter lot could go, they were only there as an alternate way to pick whirlwinds and hunters! (Based on comments from a couple of wargamers who had bought only one pack each!

).
And the Terminator formation would then cost 870 points (effectively 875) for the 6 land raiders and 4 terminators who carry remember heavy flamers. And have no hunter (with a hunter they would cost 860 points (so still effectively 875). Thats a formation where half the firepower is at 15cm and its got a speed of 25cm.
More effective would be a lander, assault marines and armoured terminators. But here that costs 400 + 200 + 700 = 1300 points (half the army) for an assault of 8 CC3+, 10 CCMW3+, 4 FF3+, 6 FFMW4+ (8 normal hits and 9 2/3 MW hits and two chaplains). Hopefully it wouldn't get shot down!
But even so its a formation with a real mix of firing types (and ranges) and quite expensive as a formation to fight assaults, I'm not sure even as an air assault formation it could work that well beyond the first shock and awe attack (being down to just the terminator formation after the first combined assault).
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