The advantage of the concept of the "scholarly base" is that it is, in principle, non-finite. If you think of your ability as a scholar in terms of i.q. (how smart am I? Am I smart enough?) then you are pretty much limiting yourself to a single measure that seems more or less fixed. I know I will never be taller than 5'8", for example, so if I had a similar number assigned to me as a scholar, and was told I could never exceed that number, it would be pretty depressing.
The scholarly base can be expanded as much as you want. It is a "growth" model rather than a "fixed" model, to paraphrase the ideas of the psychologist Carol Dweck, mentioned by Brownen in a comment on a previous post. For example, you can buy a book and increase the size of your personal library, network and increase the size of your scholarly community. You can learn another language, make forays into new fields. You can work on your prose style or your time management skills. All those are aspects of the base and all are, in principle, expandable. I suppose "how smart you are" is also a part of the base, but it is only one variable among many. Anyone with a PhD is smart enough to expand their base in various directions.
There are limits to a scholarly base, because we don't live to be 1,000 years old and thus don't have time to learn everything we should.