I'm currently working on a Multiplayer Tower Defense game, using ImpactJS & Node. I seek some clarification about how to handle projectiles from towers, let me explain.

So the server is running the master game, and the clients just follow the instruction from the server. Lets say there is about 20 towers on the stage, all needs instructions for which creeps to shoot at. Now lets say each towers fires twice in a second, that's 40 shots each second, (worst case scenario) which is 40 request per second to each client, would't this casue alot of stress to the server, saying that we have 50 games running the same time. So what i am really asking, is this method inefficient, and is there a smarter way to handle all these instructions.

Thank you.