The bunkai that I have seen have (has? is bunkai singular or plural?) overwhelmingly been against a single attacker, very often starting from a grab of some sort. Yet, being attacked by several people at once is so very common--shouldn't that be well-represented in kata also? Perhaps it is and I haven't seen such applications.
The kata presumably evolved from the Chinese forms through people trying to defend themselves--what were the typical attacks at the time? I would expect more defenses against weapons and groups but I see mostly the residue of the older native Okinawan grappling techniques. There are some defenses against staves perhaps but I haven't seen much else. The one-shot, one-kill philosophy seems to be how multiple attackers are handled.
The kata presumably evolved from the Chinese forms through people trying to defend themselves--what were the typical attacks at the time? I would expect more defenses against weapons and groups but I see mostly the residue of the older native Okinawan grappling techniques. There are some defenses against staves perhaps but I haven't seen much else. The one-shot, one-kill philosophy seems to be how multiple attackers are handled.