Ok,I wouldn't trust everything on narutopedia.It wasn't exactly written by Kishi.
Yes Hiruzen was called the god of shinobi,but going by what Madara said,Hashi was the strongest.He beat EMS Madara and nine tails.Really,come one that's got to make him the strongest hokage.
Madara never knew Hiruzen, do u saw Hiruzen in his Prime ?
I doubt that.
and we saw 1-2 Chapters about Hiruzen in his Prime and we also saw 2nd Hokage.
Hiruzen wanted to sacrifice himself and said "I am the strongest of us all, I will not die"
Stronger than 2nd and Madara got raped by Hashi before he got to know about Hiruzen.
And btw, Hashi was Hiruzen's Sensei.
Ofc, Kishi wrote in the Manga, that Hiruzen was the strongest of all Kages (Mizukage, Raikage, ..) and dominated all Gen/Tai/Kin/Ninjutus.
is this thread about hashi and hiruzen or how to post a picture on a thread
This^^.
As for your second question,not all,the second Mizukage and second Tsuchikage were apparently the strongest as far as I know.
And the first hokage,Senju Hashirama,was the strongest.
There it began..