In ampsuite an "Artist" and a "Licensor" are always referred to separately, though they might often be the same. So for example you can create artists in the "Labels/Artists" section and assign artists to releases, which will determine the metadata that is delivered with the release to stores and the profile it is linked to on each store.
You have a separate section for "Licensors" in the Accounting section. A "Licensor" in the context of ampsuite is anyone you account to and this is who you assign contracts to. So this may often be an artist, but it could also be a third party, a label etc.
So in this case, you may create a band/group as one artist in your artist area. However if there were several members of the band and you wanted to account to them all separately, you would create each of them as a licensor in your Licensors section, and assign a contract to each licensor separately.