Hi! In order to judge the situation and give you the best possible advice, can you please tell us the gender and age of your piggies and the cage size, so we can tell you what to expect and how you can minimise potential flashpoints.
As you have skinnies, please be aware that swipes with a back leg are normal interactive behaviour. I see it regularly with sows and boars of mine. However, thes swipes are carefully judges for hairy piggies with that extra protection. Skinnies don't have that extra protection, so they are going to sport scratches when in fact things are not as serious as you think.
Piggies won't go back together if there has been an intentional deep bite to the rump or face during a full-on fight.