WOW, I don't envy you and your problem. Mac and Slider used to get into nasty fights triggered by toys. The only way I resolved it was I banned them from playing with toys in the house and I keep them separated outdoors where they can play with all of their toys.
The worst fight I've ever had happened last Spring when both guys were seniors. I'd kept them separated for 5 or 6 years when they were outdoors and decided to try letting them out in the yard together ... it was a HUGE MISTAKE.
They got into a terrible fight and Faith and Bruiser joined the fracas. Bruiser was soon out of the fight but I couldn't break up the other three, even with water, hitting them on the head, etc. Finally I took my heavy cord jacket off, wrapped it around Slider's head like a blindfold, then punched Mac and Faith in their heads with my fists until they stopped the attack and backed off, then I walked Slider back up to the dog pen, took the makeshift blindfold off, and locked him in. All four dogs were very bloody so I rinsed them ... I swear I was so angry I could have killed them so I had to come into the house until I cooled off.
I'll never make that mistake again, and keep them separated outdoors until one of them goes to the Bridge.
GOOD LUCK with your problem, hope you don't have to go to these extreme measures to resolve it!!!!
Gayle, Faith, Ledgie, Scooby
At the Bridge: Andy, Abbey, Tasha, Tex, Echo, Yukon, JR, Too, Niki, Bo, Ringer, Kelly, Honey, Mac, Slider & Bruiser