Forge Seer Marshalling: Two Destroyers or One Behemoth

I may have miscommunicated - I was intending to compare two Forge Seers, two destroyers, to two Forge Seers, one Behemoth

I go with Destroyers on Seers. All caster that I take Behemoth with want him in their battlegroup.

Well, isn't better to give the Behemoth to your warcaster instead? Else just give it to Malakov1....

For marshaling Destroyer seems much better. It only needs one focus point per a turn on shooting, while Behemoth needs two. If you keep the idea to have one Behemoth and two Forge Seers, it is better to give Behemoth to your warcaster and only cast Empower once and fully boost two shots with Power Up, until it have the charge range to the enemy.

Personal preference is 2 Destroyers. Behemoth is going to be more focus efficient, in terms of number of boosts from the Empower focus.

But:
(1) It makes the marshalling Forgeseer a really tempting target, and there are plenty of lists which can reach out and get to him (Ghost Fleet, for example);

(2) More boxes from the Destroyers. I find this important, as it means that with a few jacks in the caster's battlegroup, I'm starting to get to the level where opponents need to use their ARM cracking list. That gives a benefit in list selection, as you can make a reasonably informed judgment about what is coming and choose your list accordingly;

(3) Greater ability to spread out. In SR2017, it's nice to be able to send a jack and solo package towards a zone, even if that zone isn't the one I expect to see most the fighting. I'm happy doing that with a Destroyer + Forgeseer, much less happy sending Behemoth further away from the main action - his Bombards will still get work done, but you've paid for (and want) his considerable melee presence too;

(4) Behemoth's focus efficiency only matters in some cases. I tend to use Bombard shots as high-ish POW direct fire weapons, with the AoE as a nice benefit, only occasionally actually trying to maximise the AoE consequences of the shot.

In that context, if you get the aiming bonus with a jack, even a Khador
jack doesn't need to boost to hit low-DEF targets like other jacks. And
if you're firing at something like a jack, you really only want to boost
damage.

If you're trying to snipe a solo or key model with arcing fire, you need to boost to hit, but often don't need to boost damage;

(5) I tend to be less bothered about losing battlegroup buffs on Destroyers (as melee is decidedly secondary for them), but am more bothered about losing that on Behemoth.

It's worth mentioning that a Behemoth with Crush and two focus (and hopefully Boundless Charge) will do a ton of work, doing up to 10 boxes more damage than he would with three focus but no Crush. The difference is especially significant if he's going in on a target with an ARM buffing spell that Blessed allows him to ignore.

Kill the Forgeseer marshaling him, have your caster take him into your battlegroup. Do that first turn of the game if you know you can't stop him from getting shot. I mean, in your next game, now that you have the benefit of hindsight.

Also, if you know Bigsby is going to be stationary forever, why not have the Forgeseers at least walk forward and start chucking spells around or empowering your battlegroup? Even if you want to keep one of them near Behemoth in case she rolls double-1s or something, you can at least have the other go do something useful. No reason for ALL of those 33 points to sit the game out.