This concept, which I have found recently in several sources, means developing several skills to a relatively high level, without worrying about whether you are the absolute best in any one. For scholarship, the most important features are these:
erudition; knowing your field
creativity: having the ability to develop original, creative ideas about your material
writing: being a good prose writer
organization: having good methods for organizing your research
work ethic and drive: really wanting to publish as a top priority, and putting the work in
Looking at myself, I have some degree of erudition, and a high degree of creativity, and some serious prose chops. I am also motivated, but sometimes lazy. My weakest point is organization.
If someone just had one of these attributes, it would not be enough. You probably need to be good enough in most of these categories, but someone who is really good will be very good in several of them.
Where things really kick is in the combination of skill, so that someone is erudite and creative, and can also express their ideas in elegant prose, and can produce three or four books over the course of their career. That person is a star.
Another person who is super erudite, can write ok, is super well organized, and works hard, also writing books, but without much creativity. That person might be a star as well, with a different profile.
The erudite person lacking all the other qualities is not a star, or even a good scholar. It doesn't matter if s/he is even the most erudite person on the earth. The best prose writer who lacks all the other ingredients is not a scholar either, or the creative person without enough erudition, etc...