The Harris Hawks in that program (see John C. McLoughlin in "Nomen" - 25.3.98) sometimes hunted in groups larger than two I think - maybe four or five sometimes, though it was stressed that this was unusual in modern birds almost to the point of uniqueness. There were two different roles at least though I'm not sure if there were any more than that.
The Hobby falcon hunts swifts in pairs, and there was until recently a bird, I think from NZ which filled the woodpecker niche by having one sex (M. I think) with a heavy chisel-like beak for opening up the wood, and the other with a completely different tweezery beak for picking out the grubs. Extinct of course, and it serves them right for discriminating against singles!
Pelecans have two modes of hunting - dive-bombing like gannets (and boobies?), and paddling along in a tight U-shaped formation with the open end advancing, and simultaneously dipping their beaks in together. Some individuals, I believe, hunt one way or the other depending on circumstances
Could dino's have matched mammals' complexity in their hunting cooperation? Do any non-primate or even non-human mammals have more than two roles (ie the flusher and the ambusher)? Harris Hawks are well known for tackling very large prey, and many birds can even fly with a victim much heavier than themselves. Presumably they have little need for help in dispatching large prey, though they may do for prey which keeps darting out the back of a thorn bush into another one. A question arises - how would a pack of hawks kill an animal the size of a medium to large deer?
They have a problem - no teeth, and no slashing claws. These are weapons for dealing with very much larger prey in packs. Notice that cats specialise in killing with penetrating bites (and climbing) and usually don't hunt in packs. Lions are the big exception, though cheetahs and I suppose a few others cooperate sometimes. Dogs have different jaws suitable for tearing, and they more usually do hunt in packs (and avoid climbing).
If you can rip enough shreds off your prey, eventually you will bring it down. Cumulative penetrations I feel would be less effective, and the best support for this might be that very few animals do it these days. (You might mention sabrecats as a counter; fair enough. Venomous animals usually only make a small number of bites, and don't usually hunt in packs. Well, snakes can't share, can they? Ants however do display the ability to hunt in packs, but with very little brain power.)
I think many theropods hunted in packs because enough birds do to show that bird brains are capable of it (though admittedly many pre-maniraptorans weren't even bird-brained), and the fact that most birds don't is accounted for by the fact that they don't need help killing large prey, and their weapons are unsuitable for pack hunting. (Presumably the reason so many birds of prey have penetrating rather than slashing claws is that they hit their prey at high speed, pinning it to the ground, a scenario likely to favour penetrating claw design. [That comment will cause problems for me later!]. Where prey is caught in the air, without anything to press against, a slash is likely simply to knock the prey away from the predator, so grabbing hold would be better. Besides, birds with feet suitable for use as weapons tend to have the ability to grasp branches - a similar action to the squeeze-stab. Peregrine-type one-hit mortal blow behaviour is so specialised that the suggestion that it has evolved lately is likely to be true, and it is unlikely to have been a common habit for other birds.) I think teeth were originally lost to lose weight; you lose not just the teeth but also the sockets and everything else to support them, which are many times heavier.
I don't think simple, one-role cooperative hunting requires special brain power, and theropods had teeth perfectly suited for the pack mode. What exactly do Komodo Dragons do? They can't aways make a slash and wait for septicaemia to set in! Do they hunt in packs?
John V Jackson
"Please don't give a hyaena as a pet this Christmas!"