If Fall can get back on the break better so that we don't get killed on transitional baskets (this happened a lot in his last Red Claws game), he could really help us.
In single substitution, he transforms us from a small ball, switch team, to the guy with the monster in the box.
Guys like Javale McGee, Anthony Davis, Dwight Howard, and Lebron, monsters vs our small ball lineup, suddenly become puny punks against our 7'6" beast.
He becomes our body guard against their bullies.