Yes Harry, it is key that pigs have a "flight distance".
This is the opposite of say rams, where you put two new rams in as tight a space as possible (eg 6ft*6ft), so they can't back up an charge each other.
With pigs you introduce in a large space. As they jossle - -mainly shoulder to shoulder -you get a few scrapes on the shoulders but no worse than on your hand if you catch a bramble, and the odd ear bite, but soon the losing pig will decide that he is losing. if he has room to run, he will run away, persued by the winning pig. At about 20 yds the winning pig decides that it has won adn stops chasing. The losing pig runs on for another 10 yards and then sees it is safe to stop running. Order established. So about 30 yards is a good distance. If less, you need to give some chicanes (not sure how you spell it!) by way of bales, or other obstacles.
Just for info whilst oklandspigs is run by Clare and Robin Wilson, it is Robin who posts on here, so oaklands keeps his in woods