Who is the most powerful Hokage

Who is the strongest hokage?

Who is actually the strongest Hokage? It would be such a simple question and answer if Kishimoto just gave us a straight answer. But instead, Kishimoto provides us with various pieces of information throughout history.

Before the Chuunin exam Sarutobi has been highlighted as the shinobi genius. The manga stated that he quickly surpassed both the first and second from a young age and was widely known as a professor. We also learn later that the first and second died in war, while the third and fourth sacrificed their lives to use the demon god.

Chuunin Examination Era + Beginning of Shippuds Minato was considered the strongest Hokage. Remember when Orochimaru used Edo Tensei to resuscitate all of the dead Kages - Sarutobi was most afraid of the Fourth. For a while everyone considered the fourth to be the strongest shinobi. I'm not sure if that's because they never experienced the first, but it seems obvious that Minato was the powerhouse. Everyone kept saying - if the fourth was here, Orochimaru wouldn't be a problem, etc.

Later Shippuden when Tobi begins to act and Madara is revealed Hashirama is the god of the shinobi. He is portrayed as the strongest of the four, even recognized by Minato. He is the only one who defies Orochimaru's control. Madara Uchiha also considers everyone else, apart from Hashirama, to be insignificant.

What bothers me the most is the fact that Sarutobi was not alarmed and was able to handle the fight against both Hashirama and Tobirama. Minato was the source of his fear.

And then later on, Hashirama just seems to be on another level. So I guess I have to redefine my question. Was Hashirama always the strongest Hokage, or did Kishimoto develop his strength later? Or is that simply not possible to determine?