I thought it was weird having units for more than one player starting in the same sea zone. Does this mean that when creating a map it is possible to put units for more than one player in a sea zone or was that just a fluke?

Nevermind, I just tried to experiment with it but it doesn't look like map making is an option yet...

OK, never mind again. Map making IS an option. I just suck at it and don't really know what I'm doing

The same sea zone starting was a configuration bug.
User created scenarios check and prevent this conflict.