At the Elevation Polish restock of the 7th of July, I snagged the pretty Sea of Crete, one of the small batch prototypes. It was written in the description that it was very similar to Bohai Sea but I had to buy it anyway... Last year, I spent one week in Crete and it was so amazing!!! Crete is really beautiful!!!! ♥ So, I had to buy it, just because of the name! :)
Bohai Sea is on my index and my ring finger.
Sea of Crete is on my middle finger and pinky.
As you can see, they are very similar! Bohai Sea is just a bit darker.
So, IMO you don't need both!
Except if you weird like me and you just want a polish because of its name :P