Board Thread:Naruto Discussions/@comment-28846843-20160625201600/@comment-26773508-20160627043017

Yep, exactly what @UltimaDude said. DB4 says Hiruzen showed more talent than Tobirama from a young age. That means a young Hiruzen probably learned jutsu faster and more efficiently than Tobirama did, and kid Hiruzen likely displayed more intelligence than kid Tobirama. That doesn't mean kid Hiruzen was going around thrashing Adult Tobirama. His talent at jutsu was greater than that of Adult Tobirama, but Kid Hiruzen still had much to learn, while Adult Tobirama was already a battle-hardened slaughterer of Uchihas. Hiruzen must have fully surpassed Tobirama only in his early adulthood or when he was around 18/19 (when he was declared Hokage). No way kid Hiruzen went around kicking adult Tobirama's ass.