Without a doubt, Ultron's sudden premature awakening caught Tony Stark and Bruce Banner, the two "fathers," completely off guard and left them somewhat at a loss.
It had not been activated according to plan, but rather awakened by the Mind Stone among the Infinity Stones.
As a result, neither of them knew exactly how this Ultron differed from the one they had envisioned.
After all, they had witnessed the power of the Mind Scepter when Loki invaded with the Chitauri. Even an elite agent with professional training like Hawkeye could not withstand it and would be completely mentally controlled in an instant.
Moreover, according to the intelligence Black Widow had brought back, Baron Strucker had been using it to conduct supernatural experiments beyond description, creating several superpowered individuals and mysterious conceptual weapons.
So no one could guarantee that this Ultron would become the helpful ally to the Avengers, or even all humanity, that they had expected.
Especially after Dr. Banner discovered that none of the protective underlying logic he had designed worked, and that Ultron behaved even more independently and autonomously than most humans, completely unrestricted by anything, he was utterly dumbfounded.
Likewise, Tony Stark finally realized that Raymond's earlier warning had not been alarmist. Strong artificial intelligence was simply beyond the control of modern human society.
Over the following days, they continuously evaluated and tested Ultron. The results showed that, in simulated combat, the Iron Legion commanded by Ultron could practically crush JARVIS.
More precisely, the former was a dimensionality-reduction strike against the latter. Even genuinely professional generals would struggle to gain the slightest advantage against Ultron.
Under normal circumstances, if they wanted a remotely even fight, they had to reduce the forces controlled by Ultron to half, or even a third.
Yet even then, its win rate remained