You have a lot of tiles, but because you're an intercontinental audax kind of guy, a lot of them are probably spread out. So your cluster and max square are pretty small. Have a look at page 1.
The Max Square takes dedicated, focused 'exploring' to expand. It can be quite fun though.
13821 tiles, average of 2.936 km per tile
Max square 10x10
Max cluster 348
Is it good?