An “Artist” can be an artists for a recording, an album (release) or both. When adding an artist, just add the entity (be sure search first). If there are artists with the same name but different people, be sure to add in disambiguation comments (what distinguishes them).
Where it will matter whether they are the album artist or not is when you create the release.
See the following for further details:
I looked at the links you supplied, and to be candid, it’s not clear that “World Drummers Ensemble” is a “group;” it could be a “work.” a “project” or an “event” by the artists listed.
You’ll have to do some more (extensive) research to confirm if they are, in fact, associated with the group. Google may not be able to supply the info you’re looking for; you might have to reach out to the artist/label/studio/etc. for details.
The artists have, what look to be, existing entries:
When creating the release, if they are the members of this group, I would use the “Album Artist” field of “World Drummers Ensemble” and in “Artists,” list them out individually.