I have very few Greek coins and they are all fairly small but reasonable condition. There is no pattern to my collecting of these, they are just examples I was attracted to at a reasonable price.
This whole subject is an extremely difficult one with different kingdoms issuing their own coins at the same time as others. Greece during the "ancient" period was really a whole group of nations rather than just one. The coins also tend to be very expensive compared with Roman coins and I will only occasionally be able to afford them.