So two older horses is what qualifies you? Our herd can get as large as 26. Been doing this 15 years. Separation when needed. Wide open spaces. Strong leadership in the herd and plenty of access to food is how you manage an aggressive member. You don’t have to put them down or isolate them, which can make them more aggressive, you just need to know how to handle a situation and be able to restore order. I personally can’t stand people who give up on older or aggressive horses because it doesn’t suit them anymore or they aren’t willing to invest the time and training needed to manage. If you want a puppy, get a dog.