There's one very big assumption in this question, which is that we know - or agree - on what "Greek" is. The people we call "the Greeks" did not see themselves as one people. They did not see the Peloponnesian War as a civil war. National identity is not a neutral topic and the modern Greek independence movement has played a huge part in defining peoples who were never united in antiquity as one group. And when modern writers talk about "the Ancient Greeks" they're usually talking about the Athenians, even though there's really no reason to take Athens as a measure of a standard Greek city except that's where we get most of our literary sources from.

Identity and ethnicity discussions are rarely neutral and different authors will define the world in different ways depending on the issues that they are facing. When Herodotus is talking about the Persian War and defining the Greeks against the Persians he focuses on criteria (like language) that seem to possibly include the Macedonians... but maybe not since Macedonia was a vassal state of Persia at the time. During Philip's conquest the issue comes up and the Greeks being conquered and absorbed into Macedonia don't really treat their conquerors as Greek, though Alexander tries to win over his insubordinate vassals by portraying his attack on Persian as avenging the Persian War for the Greeks. Modern scholarship isn't neutral on the topic either. The modern nation of Greece defines it's borders along the claim that Ancient Macedonia is Greek (and a fascinating take on that national project can be seen at Vergina). The tension between Greece and the Republic of Macedon (mostly quieted down by now) provides a clear case that defining Macedonian ethnicity is not a neutral topic in modern scholarship.

If you're interested in the topic of Greekness, you might start with Jonathan Hall's Hellenicity. There's a lot to go to from there, but I think it introduces the problems of the terminology very well.

So there's that huge caveat to start with. Now, some scholars like to define identity in terms of language and Ancient Macedonian was a dialect of Greek or at least a very closely related language. During the fourth century it gradually fell out of use in the Macedonian court, accounts of the life of Alexander depict him speaking Greek and only resorting to Macedonian when he's distressed. Politically - if we can even say that there is a Greek model of politics - it is very hard to say. Most of our sources come from during or after the reign of Philip II and suggest that he made drastic changes, so it's not really possible to say what Macedonia really looked like before this time.

So, basically, you've asked a very complicated question! And I did not really help to address the first part. The Blackwell companion to Ancient Macedonia (edited by Joseph Roisman and Ian Worthington) is I think a good and reasonably accessible place to start with a good introduction to the sources and what we can reasonably reconstruct about Macedonia before Philip and Alexander (also you can read a good deal of it on google books if library access is an issue).