I do agree Nagato is underrated especially with the
Scenario 1: Nagato's Paths can be of great use especially if Sasuke and him work together. I believe Hashirama will win but it would be at mid-high difficulty. Deva and Asura paths will play a huge role in assisting Sasuke on the defensive but they would lose eventually.
However in Scenario 2 Hashirama absolutely wins as CT will not over power SS. Nagato's CT was maybe 1.5x the size of 50% Kyuubi AND SS was ATLEAST 15x the size of 100% Kyuubi when counting its hands and about 2x when not counting hands.
Usually size doesn't matter when comparing non avatar jutsu but with CT its all about gravitational pull. EVEN IF Nagato's CT was bigger it still would struggle to pull in SS. It would probably kill him attempting to do so without Hashirama even using it to fight back.
Lastly! If Nagato could make a massive CT to pull in SS it would
require concentration which Hashirama's Choujou Kebutsu would not allow as the constant damage output would be too much considering he can destroy the boulders being sucked in, smash sasuke's susanoo and attack Nagato head on simultaneously.
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As you see in the image above its literally blitzing through tailed beast bomb/PS Sword spam and still wrecked 100% kyuubi AND Perfect Susanoo.