I read THIS article on expert generalism a month or so back (thanks to Simon of Ancestral Movement for the link). An expert generalist is a term normally applied to someone who has a wide range of knowledge and creativity, and whose innovations rest on a foundation of this broad knowledge base via the ability to jump between these different fields of inquiry quickly and effectively.
The article lists: Openness to experience & love of the learning process (defined in the article as 'Need for cognition', but I like 'love of the learning process' more) as two of the primary traits of an expert generalist.
Despite at some times running dangerously close to being 'jack of all trades, master of none', I find the approach of the expert generalist works well when applied to the broad area of movement training and physical//somatic exploration and cultivation (and Life in general!).
For me, expert generalism in a physical culture context consists of both theoretical knowledge (of a wide range of topics) and body knowledge. This body knowledge consists of both sensory (sensuous) information that can be cultivated with increasing accuracy despite its subjectivity, and also the sensori-motor patterns to do all types of different physical activities and movements (something I call a movement lexicon).
An example of the sensory awareness body knowledge is the cultivation of the awareness of visceral sensations (visceroception) that is key to my 'early warning' system for illness. I find this body knowledge very useful. I can't give you any studies about this, as I mentioned, it is by nature a subjective knowledge. You'll have to practice, explore and see what happens for you.
I feel that embodied knowledge has a realness and aliveness to it that make me personally rate it more highly than theoretical knowledge (Just my opinion! Most likely not shared by many!). I'd much rather be able to do something, and not know how it works; than know about how something works and not be able to do it.
Now that being said, obviously the best combination (especially with things related to the physical body) is to be able to both do them and to know how they work, and be able to explain both aspects to others - as I'm sure most people will agree.
The best people I've met in the field normally have a high degree of both theoretical and practical knowledge. This practical knowledge doesn't necessarily mean they are amazingly talented at the physical skill-set, but that they have a high degree of experience with the physical skills, and teaching them to others, too.
Interestingly, in Michael Gelb's awesome toilet book How to Think Like Leonardo Da Vinci, Gelb states descriptions of everybody's favorite renaissance man (super expert generalist), Leonardo - proclaiming his amazing strength, dexterity and body knowledge of things like equestrian, fencing and swimming (to go with his well know intellectual brilliance and artistic talent).
Indeed, the book details how Vasari describes the citizens of Florence turning out to just watch Leonardo walk down the street, such was his "more than infinite grace in every action".