You may be satisfied with it, but is your pig? I had the biggest commercial cage possible at the pet store, came at a cost of $100. I then upgraded to a 2x7 cavycage, which I bought for $35. The moment I put my boys in their together I noticed some thing, oh yes that's right: They were happy! Why don't you save yourself the trouble of arguing the big/small cage thing and go out and make your pig happier, make her a larger cage.
Oh yes, and about that singles boars thing, if breeding boars can't live together, then why don't you make them happier and stop breeding. I don't really care if you're breeding to help with genetics. Have you visited
www.cavyspirit.com? The pig rescue near me has over a hundred pigs up for adoption. How about, instead of contributing the problem, you help and adopt some of the pigs. I know that even the UK has pig rescues, because there are several members on here from the UK. So don't say there aren't any around you. Oh well. Bottom line: Until we see piggers in bigger cages with enough space to run around then we won't be happy, and most of your pigs won't be either.