Who picked the weapons for the Ninja Turtles?

There are four turtles right. There is the blue one Leonardo, who is the leader, the rebel red one, Rafael, the goofy orange one, Michalangelo, and the smart purple one, Donatello. Now the leader has a sword, the rebel has daggers, and the goof has nunchucks, but Donatello, the supposedly smart one, carries a stick. A stick? It's not even metal. It's a piece of wood that can easily break in half. I mean splinters do hurt like a bitch but can't really kill you. He'd have better luck just throwing furniture in the room at someone.If he is truly the smart one he would have a machine gun. Shredder wouldn't stand a chance then, but I guess that wouldn't be ninja like. Or he could always just beat people with the gun, you know a little pistol whipping. And why do they all have to have different weapons? What's up with that? I know this is kinda very Jerry Seinfeld-esq but it's just something to think about...