Hi Tonia.
Siblings will be siblings is right. Maybe it's good that they are open with each other in disagreeing. Hopefully, when push comes to shove, though, they will have each other to rely on. Out of my 10 grandchildren - I have 3 grown grandson that live upstairs and sometimes it feels like the ceiling is about to cave in, but they know they love each other. They are 20 (21 in Feb), 18 and 17 and are all so different from each other and probably all fighting for control and to be first.
When my 4 kids were younger and would fight (which was more as they got older), I'd try to just let them figure it out. If someone ended up pushing the other or making the other cry, I'd just say, you have to fix it and they would. They all have their own families now and they seem close.
Now with me and my siblings - we were raised in a very rigid home and instead of arguing or talking - I always felt like we were more like a mafia family. "Hey, let's go for a ride", both knowing that it's to be killed off, but not saying it. I think I'm the only one who would actually tell the others how I seen them and was honest - everyone else - mafia silence. I didn't mind telling my brother that he's pushy with his opinions (we all know that), my sister would butt in too much and talk bad about everyone and twist things (we all know that) and my other sister being too hysterical over little things (we all know that). I'd ask what they seen as my problem and no one would answer. I never understood why try to keep secret something we all know. But anyway, I ended up disowning myself from my siblings - so I don't think silence is the way to go. Oh and oldest siblings always tend to feel superior in some way (I've never seen any that didn't).
You seem to have a lot of patience and love for your children.