One thing missing from the first movie: Don's intellect

[Leonardo_Warrior_Turtle]

I just watched the first movie again and I noticed something. Every Turtle had their personality down pretty well, except for Donny. He really didn't use that famous intellect we are used to seeing. However, he does make it up in the next two movies. Still, I'm wondering why he didn't do anything super smart. What was wrong with the writers?