Hawkwind, I agree totally.
This is one of the reasons I dont like Swarms - whether one or a million bites - you were still taken down by a normal size spider/etc.
Now based upon RL: I remember seeing doco's saying that elephants, rhinos, etc stampede from Army ants as when they swarm they can take down ANY animal in its path. Sure millions of ants may die but when their trillions of ants, who cares? its for the good of the colony. Apparently the figure that sticks in my head is that they can kill and strip an animal in minutes, leaving bones behind. I saw this doco more than 20 years ago but that scared the Sh*t out of me!
Also, in RL, a swarm of huntsmen wont do anything (I believe their fangs wont puncture human skin, let alone get through clothes, etc) but they would scare the heck out of you. Maybe a RR of go catatonic? (Cascading shock rules from one of the HB's?) And the WA(oz) Red-Back Spider AKA Black Widow would kill in minutes or seconds. (a swarm that is).
Any HARP monster rules would have to be very specific and have been thought out very well.
You couldnt create a "Generic Swarm" a jskinny has requested.
Just my 2cp.