Zhukov said:
I strongly suspect that you, my dear sir, are bullshitting like a pro.
Where is it said that the Reapers have free will and are only instructed by Glowing Space Kid?
Note that during the conversation with said Glowing Space Kid, he says, "The Reapers are mine. I control them." He also describes the control ending as him being replaced.
Members within a hive-mind like collective do not posses individualistic though, or individualistic identities, case in point The Collectors, and The Rachnai, and to an extent The Geth, sans Leigon.
If the Star Child truly possessed 100% complete control over The Reapers, Sovereign, Harbinger, Leviathan, and the other Reapers would not have names, or different personalities. They would all refer to themselves as the same being, the reaper on Rannoch wouldn't have used Harbinger's name.
That The Reapers have names show individuality, in their names, their thoughts, and their actions, which means they cannot be controlled entirely by the star child.
He does possess massive power over them, but they are not fully under his control.