Actually, the Hellfire is semi-active, and depending on the version, needs either constant laser or radar illumination. Also, the Longbow can only illuminate one target at a time. The way they get away with attacking multiple targets is by changing the missile to a 'lock on after launch' mode, which lofts them up higher and gives the firing platform a little more time to think and switch targets.
Now, as for 4 Longbows taking out 32 tanks? They wouldn't really do it in passes. They would find some place to make pop-up attacks and just ripple the missiles off, likely alternating between one ship firing and one designating targets semi-behind cover. You'd still end up with a big pile of scrap metal afterwards though :twisted:
EDIT: Wow, there was a whole other page. I wonder why I didn't get that nifty little '1,2' thing in the corner until just now?
Well, I'm assuming the quoted material above was russian, as it seemed to come from the russian forums here. Just a hunch, you know...