Hiruzen's durability is irrelevant to how he can defeat Raikage. Who cares if he can't tank his attacks, when you have Bushin feints and Adamantine staff (which either doesn't break or need to activate his higher levels of Nukite).
Still irrelevant, as Hiruzen cannot hurt the Raikage, and the only move in this entire matchup that can hurt him, is the one fingered nukite.
None of these characters are near the intelligence of the professor. This man figured out the priorities of the Juubi Jin, having just meant him in minute. An element master, as he is, is going to figure out the prioritizes of Raikage's Raiton, how powerful his raiton is, and how durability his body is. He WILL figure out his only option base on intelligent feats.
Nothing but your assumption. He basically compared the truth seeker balls to Onoki's jinton(which he had apparently seen before), and worked out it was a better version of it. No evidence that he would figure out the raikage's weakness. Hell, even if by some miracle he finds out, it's only applicable if the raikage actually uses the one fingered nukite, and I see no reason for him to.
He will need higher Nukite to breach Enma's defense. Even if isn't going to use higher Nukite to kill Hiruzen, lower version are still good enough to wound himself (like in canon as he would have died if he used 1 finger on himself), which Hiruzen focuses his damage to defeat him.
He heavily wounded himself with 1 fingered nukite in the manga.(gave him the scar), it didn't kill him. Either way, his 3/4 fingered nukite should have no problems in damaging enma(easily went through a mud wall plus Dodai's rubber IIRC), and I see no reason for that to cause major damage to the raikage.(that is if Hiruzen even comes up with that strategy himself, which won't happen anyway.)
-Hiruzen has no way of putting him down.
-Repeated use of clone feints/elemental spam will wear himself out
-Enma is fodder to the raikage
-3/4 fingered nukite rapes Hiruzen/Enma
-There's black lightning that can be used at mid range, but I won't talk about that has he has no featsthere.