This question was actually phrased fine and I have a very complete answer for you. To some extent yes, the borders of Greece were consolidated in the middle of the Greek Archaic Period. However, this was only after Cypselus and Periander had made walls for the city of Corinth after fighting Megara for years and after Pheidon of Argos consolidated more imaginary like borders with some forts around Argos at the Greek poleis of Tegea, Sicyon, Mycenae and Tiryns. Sparta also did the same thing under Theopompus and Polydorus, the kings that got Sparta to take over the Lakonian Plain and the territory of Messene, the land of Nestor. The poleis Phigalie and Megapolis acted as the Spartan’s natural defense poleis against enemies, where they mostly battled the Argives without a wall to help them defend. Also, It should be noted that after the Spartans conquered the Messenians, it was known not to go into the Eurotas Valley unless you wanted to battle the Spartans. This was the same case for anyone that went into the Valley of the Argives past any of their border poleis. Megara was then built a wall to keep out the Corinthians after winning independence from them in a couple of wars. Then, the Athenians and the people of Attica and the people of Plataea and Thebes combated each other a lot much like the Archaic Spartans and Argives but on a smaller scale and eventually made walls and forts. Then every Greek knew the Thessalians were north of the Hot Gates or Thermopylae, just north of Greece, so their boundary was the mountains themselves. This left only the Peloponnese territories of Arcadia, Elis, and Achaea to defend their borders the old fashion way.

When these smaller poleis were attacked by another opposing polis, they simply got into the phalanx fighting formation and fought the enemy. And after enough fighting had ensued, it was decided by the real or the perceived victor where the new borders between the two fighting cities were. Since these smaller poleis controlled their borders like this, their borders changed a lot throughout the Archaic period since it was a period full of war. So this was how the smaller poleis around Greece decided their borders in the early Archaic Period. Also, it should be noted that once the Olympics started, the Olympians (the citizens of Olympia) did not get attacked too much because Olympia was considered a holy site for the Greeks to praise Zeus. So when it came to boundaries in Greece it was made it two ways, either by a man built wall or a geographical barrier like a mountain or river. This was why all Greek battles were either fought by mountain ranges or on open plains in Greece proper because they chose to fight away from their city if they could. Sceond, battles between the ancient Greeks occurred in these places because this is where ancient world armies would meet when on campaign, in a mountain pass or a plain on either side of that mountain pass. This was because there was only one ideal way to get to most places in Greece for an army since it was so mountainous. These geographical determinants made it so the borders in Archaic Greece got pushed around and modified in the hinterlands of the Greek poleis. So in sum, the Archaic Greek world was initially created by a bunch of small border disputes, much like disputes between the five villages that eventually made up Sparta, that ended up making the Greek poleis we know of today. A process that took place not only on Greece proper but on the many Mediterranean islands that had Greeks dwelling on them.