I have four girls. They do rumblestrut when they are hormonal, two of them also popcorn and squeak strangely around the cage as they are all pent up. After this they tend to get possessive and rumbling about where they want to chill out on their own. No matter who the dominant piggie is, the hormonal one rules the cage at that time. The other two piggies do go that extra mile of worked up though, chasing the other piggies around the cage trying to mount them. But boors do that too and it only lasts a couple of hours every 3 weeks or so for the girls.
Having introduced one pair of girls to another, after going through the bonding process it has taken about a further 4-5 weeks of being in the cage together for all the dominance squabbles to stop (which used to rear up once a week or so) and for everyone to accept the status quo. They used to sleep in their original pairs together or on their own, but now they mix and match and cuddle up together. And there is no sperm rod cleaning or grease gland cleaning to be done with my four!