I agree that it all depends, but I also agree from my own experience that pigs don't have a good sense of others' - they are just blissfully curious!
I have sheep, donkeys and currently two weaners all on the same field, but the weaners are in an electric fence pen that they respect, and this works very well for all involved.
But on one occasion when I moved the pen on, the piggies were running loose for a very short time, and went straight up the donkeys nose, repeatedly... which the donkeys didn't appreciate at all, and they started chasing them around rather aggressively.
Taught me a lesson - I now move the donkeys to the garden or shut them in temporarily when I have to move the pigs. Also the donkeys are now restricted to their own summer grazing track by electric fence line, so should the piggies escape unnoticed they can get out of the donkeys' way.