Hashirama and Tobirama weren't a big deal in Part 1, they were presented as "fodder Kage" of their time. Anyone who's been following this series since the start knows it. Orochimaru summoned them just to lower Hiruzen's morale, if you remember the fight, he was easily holding his ground 1v1 against Hiruzen before Edo Tensei.
Ginkaku Kinkaku are indeed strong but they did lose to Darui and Shikamaru's team. In comparison, Hashirama would've completely raped them.
You say that because he invented all those techniques, he is the strongest. But you completely ignore the fact, which was stated in the manga, that those jutsu were imperfect. Orochimaru and Minato improved his techniques, it's stated in the manga. Tobirama can't use FTG as good as Minato (he doesn't use Kunai) and he can't summon full power Edo Tensei like Orochimaru or Kabuto.
It's just like comparing Minato's Rasengan to Naruto's Rasengan Barrage / Rasen-Shuriken.
What I'm saying is Tobirama may know a lot of techniques but he sucks at all of them.
So I rest my case... they're not among the strongest Kage or strongest shinobi, it's just sensless hype.
They were not presented as "fodder kage"
1. Hiruzen KNOWS their full power so if anything st first he's thinking...SHIT.
2. During the fight, they note Tobirams using Suiton from nothing
3. Hashirama creates a Damn forest
They may not have been at full power... And was confirmed to be a FRACTION...but they still were keeping him going at a mere 10% strength. Also, didn't you just help my case. Orochimaru was MATCHING Hiruzen one on one....pretty good for an old man...once again...old man not young prime youth.
Once again....Darui only won because of PLOT...Darui was being pulled into the gourd GAME OVER. Then the plot says even though a sealing process is already occurring, he can change his word and get a get out of raped free card, and proceeds to surprise the brothers...who at the time had never encountered this.
Additionally, Kinkaku was in a blind rage sonaturally he was being careless. Even then it took a unique sage weapon to stop him....also, don't underestimate the Mind Transfer jutsu.
As for his jutsu...the fact they differ from those who mastered them doesn't make INVENTING them any less of a notable fest. Furthermore, he implemented them differently.
1. Because his Edos were not complete, he formed a infinite exploding talisman jutsu to make them usefull...with a titanic explosion.
2. He mainly used FTG with Kenjutsu for the Hiraishingiri.
3. He died young so theoretically he may have mastered these had he spent more time on them...and not...I don't know....sacrificing himself against the Kinkaku force.
Also, the only difference in FTG is that Minato has made the time barrier and the tagged Kunai, BUT, considering Hiraishingiri..plausible weapon attachments. And considering Tobirams mentions he can teleport a TBB...an equivalent of S/T Barrier.
But remember Tobirams is actually a Suiton user which means that everything he's shown us so far isn't even his forteit.
Lastly, Tobirams and Hashirama fight differently. Tobirams approaches with more notable one on one techniques where Hashirama produces massive scale techniques.
Despite this, Kakuzu, who was young and had no Earth Grudge Fear, Survived his fight with Hashirama, and so Ginkaku and Kinkaku probably wouldn't get raped...but still defeated due to the additional powers of Mokuton on tailed beasts and chakra absorption in general.
So once again you discredit the Hokage: Tobirama and Hiruzen