Hiruzen is really godlike...
Check these stats out, its from the Databook Kishi wrote;
Hand seals 5
This is during his old age, Strength, Speed and Stamina should be lowered, well because his old.
Now how strong was Hiruzen in his prime? That stats should have been a bit higher Making him without doubt stronger than anyone out there, since he who have the highest stats.
Here is other points too;
• Only known Shinobi that can tell which jutsu the opponent will use simply looking at his hand seals (Proof of Prowess in Knowledge)
• Somehow stopped both Orochimaru's 3rd Coffin and Shinju's Chakra Absorption
• Analyzed Obito's new found power within seconds, giving a report that's rather in full detail and how it works.
• For knowing every jutsu within Konoha, so he possibly knows FTG and Multi Shadow Clone Jutsu.
• Said to be the strongest of all Kage's and Hokage ???
I wish Kishimoto gave him more screen time, something's don't convince me...