its normal on Jetpunk that Congo is accepted for both congos.
Now you didnt give any link to a source. If your source isnt the UN but rather how every country is officially named according to itself then "the Gambia" and "the Bahamas" shouldbe included.
If we go by languistic properties of english we get "the Netherlands". English also means that any island nation is "the "
All in all I would make clear what your source is so its clear which are accepted and which arent :)