Korinth wants to grow into a major power again but it needs a steady hand as its future is shaky.
Tester’s tips
The territory of Korinth is split; there is a small area around the city of Korinthos occupying the land between Peloponnese and Attica, and couple of colonies on the western coast of Greece. It is definitely a very vulnerable position. Losing the colonies would impair your ability to grow economically as most of your resources come from there, on the other hand losing the capital city dramatically impacts your army and general morale.
Take advantage of your central position and try to make as many friends as possible. Secure the colonies and then expand towards Akarnania. It is one of the weaker states so your chances there are relatively good, especially if you manage to draw Aetolia into the war as well to help you finish off the Akarnanian forces. Go after cities and resource mines, those should be your priority.
Attacking on Peloponnese or in Attica is tricky. You have only one city (Korinthos) and it is difficult to defend it when you have to use it to reinforce your troops.
The one advantage of these divided territories is that even if you lose one area you still live to fight another day from the other.