Re: Tobirama's intelligence
I'd be willing to say a top 5 is possible
2. Shikamaru (who'll likely top his father)
After that... it comes down to people with either vast quantities of knowledge (due to age like Kakuzu, Madara, Hiruzen, or Oonoiki), or people who were naturally analytical or smart (Tobirama, Minato, Itachi).
Considering that on top of battle smarts, Tobirama is also very creative smart, studied the Uchiha, and thought of the founding principles of the Narutoverse (Village, rules, exams, Anbu, Chunin Exams)....I could give him at best 3. Which is still pretty good.