I used to have a team of mares, a mother and a daughter, and they weren’t big horses but we worked them on the mowing machine. They got along just fine together but you put them with another horse and they were cranky with that horse. So what we did with them was we turned them all out together and said let’s find out who was boss and then when they established a pecking order then things smoothed out. The other thing that helped was we mowed a lot of hay with them. Whenever you get a few wet collar pads on them, it makes a whole lot of difference in attitude. They figure out there’s something else to do besides pick on each other.
It is possible to have your animals strung out (4, 6, 8) and only have two lines. So you have a team line that comes like this (to the lead team) and yet no lines on the wheelers. Instead what you have is a tie in chain and a forked three point line hooked to halter rings and back to the lead bar or chain. This requires an equalizing double-tree set up to a lead bar or preferably a chain to the lead double-tree so there is an equalizing effect. All animals have to pull equal. There’s an equalizer with this and there are a variety of different ways of doing that. Basically the leaders step forward and pull along the bar or chain and literally pull these horses back for an equalizing effect.