When you have only one child, it is easy to buy things for the child. When you have more than one, you have to buy duplicates because they will fight. If you have money to buy only one toy, be assured that they will cry and fight just for the one toy even if only one of them actually like it more.
I had to be referee or the evil one. Either I threaten to throw the toy or whatever item into the rubbish bin or I keep. It is high time to utilise the corporal punishment. Cane is more effective because the pain is there. I used to fight with my siblings and the cane was fast to strike.
If you ever need entertainment, let only one item lying around and if one kid picks it up, the other will want to play with it. The crying orchestra will begin or the fighting will begin in just seconds. Find a chair, plug in the ear plugs if you must and eat popcorn.
Telling the kids to share is like telling them to stop running when they have too much energy.