c&c cage introducing new piggy

Yesterday I put my two boars in a bigger cage that is 2 x 6 grids. They are doing the usual stuff, teeth chattering, rumble-strutting and mounting. How long does this dominance usually last?

I'm in the UK and finding it hard to get the stuff to build a storage block c&c cage! There is one on eBay but you don't get the insert the ties or anything with it! Could any please let me know the best way to build one? I'm getting a second piggy and when noodles and the new piggy have bonded...

We currently have 2 girls in a 2x4 with a 1x2 loft and we're planning on introducing a 3rd girl and making it a 3x4 (may or may not extend the loft as well) but I was wondering what the best set up would be if they don't hit it off right away, I don't really want to do it as a 2x4 and and 1x4 as...