Orochimaru made the correct choice: if hard control was impossible, then soft control was definitely the next best option.
Using physical means to control the Reanimation Complete Edition First Hokage was far too difficult. No matter how thoroughly he planned or how complicated his methods were, he could not guarantee the desired result. But looking at it from another angle, since he had reincarnated a clear-minded First Hokage through Impure World Reincarnation, why did he have to control him by force? Persuading him with words was also feasible—in fact, it was the most feasible approach.
One should not think of "maintaining one's reason" as purely a negative effect. If one broadened one's perspective and stopped being so extreme, then even a Konoha rogue ninja like Orochimaru could reach a deal with the First Hokage... Yes, Orochimaru wanted the result. Whether that result was achieved through control or negotiation, what difference did it make?
Madara Uchiha wanted to destroy the world, while Nagato at least wanted to rule the shinobi world. Whether it was the former or the latter, neither was something the First Hokage could tolerate. Even the dead could not become completely empty of all desires. In fact, the dead might care even more about the accomplishments they had established during life. From this perspective, Orochimaru had easily persuaded the First Hokage.
Back then, the First Hokage had eliminated Madara Uchiha after he defected from Konoha with swift, precise, and ruthless methods. Now, of course, he could deal with a pair of Rinnegan even more swiftly, precisely, and ruthlessly.
As long as the reincarnated First Hokage met Nagato again and confirmed the threat the Rinnegan posed to the entire shinobi world, his deal with Orochimaru would be made with absolute certainty.
For Orochimaru, the rest was simple. Once he