Physical reactions – A Domino effect

My eldest son has a habit of acting in a physical way trying to get his younger siblings in order.  Of course this is passing on down the line.  Now my four year old son, because he so often gets a push and shove from his elder brothers and sisters is treating little ones in the same way.  Unfortunately, but not surprisingly, his reactions are not controlled and lead to hurting these little ones.   More often than not he ends up in his calm down spot and it takes me a long time to get him back in a good place where he can make things right.  I can see very clearly that it is a result of how he has been treated, and I am trying to help my older children to understand that he is acting the way he has been treated, so they need to set a good example.  I am having trouble getting this message across because in their mind they’re correcting bad behaviour.  (Still working on the roles)  At the moment it feels like a vicious circle and I am so often feeling like I’m running behind and trying to pick up the pieces.