NPC Clippers are really good at getting gang-rolled in RES sites. Not sure exactly what it is but as soon as a wanted Clipper shows up, all the NPC bounty hunter ships within a lightsecond seem to go into frenzy mode and pump it full of beams until its been reduced to glowing chunks.
Because a wing of clippers, even NPC, will often turn half the RES site into glowing chunks. They are fast, can plough through other AI and as a large ship, are an automatic increased threat. Even the AI knows a bunch of clippers waking in, isn't a good thing.