Wouldn't the name of 'Professor' better apply to Tobirama?
1. Kage Bunshin no Jutsu
Almost everyone utilizes such a jutsu. We have people like Konohamaru who're children and use it and then we have people like Tobirama, Itachi, Minato, Naruto who're some of the strongest shinobi on the planet who use it. It can be coined the universal jutsu basically - it doesn't seem to take too much skill to use it and it's such a powerful jutsu. It has also led to the creation of so many other techniques.
2. Hiraishin no Jutsu [FTG]
Must I comment. We only know two people who can use it.. one is the all mighty Tobirama who is brother of Hashirama Senju and the Second Hokage and Minato who basically solo'd a war, Obito and saved the ASF.. The concept is so simple, yet it such a difficult technique but it's nearly as versatile as Kamui.. you could argue it is more versatile.
3. Edo Tensei
This is, in a way a version of Rinne Tensei.. They both bring back people. It may have led to more people dying than any other technique practiced. Orochimaru, Kabuto, Tobirama - random group of people so it mustn't be too hard to use. Orochimaru said it's not that complicated.. devising such a technique require genius-level intelligence.
Wouldn't some with so much influence and who created so much be coined the Professor, not a feat-less man who knows all Konoha's techniques and doesn't seem to have any unique ones of his own? Mind you, I like Hiruzen, he's an awesome Hokage but I think Tobirama deserves the title more than Hiruzen.
Re: Wouldn't the name of 'Professor' better apply to Tobirama?
Tobirama gets "inventor", while Hiruzen gets "professor". It's akin to Benjamin Franklin and Dr. Rosenhein from chemistry class. Dr. Rosenhein didn't invent jack diddly, but he sure does know everything about XXX!