You can't relativise philip's contribution to the notion of the phalanx we have today. Philip's Macedonian phalanx formation, and not the greek one, is what we admire today.No, they were already in existence. Just as the phalanx existed before Philip II. As with your mention of the Agarianians, what is the point?
I mentioned the agrianians to show how philip was attached to his allies with whom macedonians shared the same blood; These allies showed a greatest faithfulness to the macedonian cause.