Hiruzen was the strongest, Minato was the greatest. Realise the difference???It is also said that Minato was the greatest ninja Konoha ever produced. Do you guys realize how many time kishi has contradicted himself in this manga? Like i said before Hashirama and Minato have gotten praised by the likes of Madara, the 4th raikage, jiraiya, and (plenty of other shinobi that i don't feel like naming lol) and they have a lot more credibility than Iruka.
Hiruzen is the strongest in terms of combat, but minato is the greatest ninja.
Minato did a lot of good things and was very strong, saved konoha, greatest ninja. Greatest need not mean strongest ya know???