[Edi]

Both. From the mechanics point of view it's WAD. All weapons that get flaming versions actually have a counterpart named "Fire ", so long bow becomes fire long bow, which is a normal long bow with a secondary effect of fire (8 AP or 6 AP, don't remember). Currently small bow and sticks & stones do not have fire versions.

It's a bug in he sense that those missile weapons should have fire versions. I should add that to the shortlist when I fix the formatting.