Cyrus Conpliments the Greeks

One of the more curious episodes that caught my eye in the Anabasis was how Cyrus was so generous with his compliments towards the Greeks. I was under the impression that given the history between the Greeks abd the Persians that Cyrus would be semi-hostile toward them, viewing them only as a necessary evil in his quest to overthrow his brother. Yet in I.7, he claims that he values them above all of his barbarian forces because he believes that they are braver and more valuable to him than the others. Was this a normal occurance? That is, was it ordinary for a rival culture to pay such high compliments? Or was this metely Cyrus appealing to the Greeks because he needed their support?