i hate people so much. all i have to say is this
when a rumor spreads, do you blindly believe the rumor, or do you keep it in mind but ultimately disregard it till you have PROOF ? If youre smart you ignore the rumor until provin otherwise ...... In other words, Hiruzen hype means zip
hiruzen's hype is not rumours, it's a fact
fact no1: part 1 scaling is much weaker than part 2 scaling. look at the very first shippuden battles, deidara vs gaara. completely different level, both would have wiped the floor with pt1 itachi, hiruzen, sannin etc. yet they're nothing out of the ordinary in pt2
fact no2: specified as the god of shinobi in the databooks. called the professor for being able to use all the jutsu in konoha. called the strongest of the hokage by iruka, the strongest of the 5 kage by kabuto. has over 1,000 genjutsu. abilities in the databook maxed out apart from the physical attributes which he lost due to the fact that he's an old man. he was known for his incredible speed, strength and powerful chakra and stamina as a young man btw.
fact no3: hiruzen's performance in his lone battle was deemed pathetic compared to his lofty standards by everyone viewing the battle. he was also hesitant about destroying his disciple orochimaru and his mentors. yet he defeated two strong edo tensei and removed orochimaru as a threat to konoha, and survived for hours with a sword through his chest, showing one of the best durability feats in the manga.
fact no4: orochimaru had perfected ET ie. both hashirama and tobirama were fighting to their full capabilities. if you can't wrap your head around that, go back to fact no1.
bottom line, a part 1 character is always going to pale when compared to part 2 characters. heck, shippuden itachi would mop the floor with part 1 itachi. hiruzen's true power is a. not scaled to shippuden. and b. he didn't get to show his best. itachi did, and furthermore got a good chance to show feats beyond his true capabilities as an edo tensei.