Usually MB will pick a title based on the cover, but the artist should be based on the actual artist.
If you know that this is The Robert Cray Band and are sure the cover is just an artist’s sales trick, then file it under the band.
At the heart, MB is about accurate data.
Quite a mess. The more I look, the more confused it is. Sometimes credited to the man, other times the band. Wikipedia keeps Band and Person in the same discography and keeps swapping terms. I’d want to find a real fanclub site or biography and see who it is credited.
I know this problem well enough. Especially with eponymous bands. On one release it’s the band, on the next one the main artist alone, sometimes both variants on one release. Most of the time I decide based on whether the band is significant as an independent entity. If the members are constantly changing and the focus is only on the eponymous artist anyway, I would settle for “credited as”. However, it is probably not possible to establish a general rule.
In the case of The Robert Cray Band, there seems to be no fixed line-up.
Knowing that probably won’t be of much help as this band can’t possibly be ignored. There are too many credits for the band…