I have noticed many people here have the problem of attacking a Big Daddy first. They feel guilty that they are the bad ones, and poor metal fellows perish on their whim. I discovered a way to make a BD attack you first.
Unequip Natural Camouflage tonic (invisibility prevents this from working).
Find a BD with a LS and apporach the LS. The BD will make a roaring noise, start spinning his drill/harpoon (for Bouncers) and take a defensive stance with LS hidden beneath.
After a little time, the BD will move closer to you and give you a hard tug, then go back to the LS. Again, move closer to him.
Repeat this, and if you will not run away after the third tug, the BD's portholes will turn red and he will start attacking you, the LS shouting "Kill him!" and the like. When you defeat him (in self-defence, of course), you proceed to save the poor lonely LS.
This will deny you the moment of surprise and the optimal choice of battleground, but for moral freaks this is the only way.