Whether Kamara actually kicked the victim, or merely landed a few shots then backed off, might mean something if you’re evaluating how to judge him as a human being. But legally, in terms of committing battery resulting in substantial bodily harm, as a co-conspirator it makes no difference, he may as well have landed every blow and kick himself. He's equally responsible.
That said, if Kamara can establish that his involvement wasn’t as egregious as the other defendants, it could theoretically make a difference in sentencing.