J.C.
Normal for this age.
What I found helpful was to buy some toys that were expressly for when my child played with one other child. I would buy two of the exact same thing. For example, they played a lot in the sandbox. So, I bought 2 red shovels, 2 blue pails, 2 identical trucks, etc. (They have to be identical, down to the color. Otherwise, they will both decide they want the red shovel instead of the green one.)
This solved most of the problems. Once in a while, one of them would decide they wanted BOTH red shovels. So I would have to step in and say (for the 100th time) "Each of you gets one shovel." and physically take the shovel and give it to the other child. If there were ever a problem where they refused to each have one and continued to fight over an item, I'd remove both of that item so neither of them had one. They learned pretty fast! : )
Blessings.