If its anything like horses the bigger the concentration of animals to an acre the more you need to worm.
Pigs well fenced in, feed twice a day. You could comfortably have two weaners on half an acre bring to weight, kill out then put the next two on the other half acre.
Less work than sheep or goats in my opinion, as long as you have really good fencing.
Good luck whatever you do I am sure it will be great fun.
HM