I don't think this is supported. Sauron stil had the Nine, and Saruman couldn't hope to compete with those servents. When Pippin is caught by Sauron's eye in the palantir Sauron speaks in a tone that suggests that Saruman is just an agent of his, over whom he has supreme control:

"So you have come back? Why have you neglected to report for so long?"

and:

"Wait a moment! We shall meet again soon. Tell Saruman that this dainty is not for him. I will send for it at once. Do you understand? Say just that!"

And even Gandalf, who had just contronted Saruman and defeated him rather soundly is wary of whether he could have probed the palantir and come back:

"Had I done so, I should have been revealed to him myself. I am not ready for such a trial, if indeed I shall ever be so".

Whatever Saruman's strengths at a distance, Sauron seems to have a much greater amount of power. Saruman may have thought to equal Sauron, but it doesn't seem that he could, if Gandalf the White could not.

-RR