I think the group shot really helps to emphasize how the big the Behemoth really is. The USCR are already a big faction, and the Behemoth towers above the rest.
The most important thing I've learned in painting my USCR, is to avoid painting solid whites, at ALL costs. Never, EVER, paint solid whites!
Well, that's three factions down, and one to go in Sync's MERCS Madness Month - this week I'll be tackling the sefadu!