How/what would you define as a "great dancer"?Technical ability? Performance skills? How well-known they become? Or all of the above?
If all of the above, various influences would have to be considered.
Performance skills would obviously be relative to fire signs, especially the Leo/fifth house archetype.
Anna Pavlova's chart has a fifth house Moon in Leo indicating a deep conditioning to convey a self image that is highly expressive and creative of one's individual identity.
She has three personal planets (Venus, Jupiter and Saturn) in Aries. They also in her twelfth house - Neptune/Pisces archetype -- 'the artist' -- signalling a subconscious connection to these fiery-natured planetary dimensions. Venus here, although in detriment, is like a subconscious itch that would have irritated her and thus motivated her into expressing the beauty (Venus) and artistic (Neptune) qualities of ballet/dance. Jupiter and Saturn's placement here signals her subconscious drive to achieve this within the sphere of her society of that period.
Lastly, the placement of her north node in Sagittarius indicates a movement towards union between her higher mind and her earthly body, and by doing this achieving inner union with herself and the divine and discovering her personal spiritual truth. What better way to do this that through dance?
In Margot Fonteyn's chart, we see Venus, Jupiter and Pluto in the fifth house (signalling that three archetypal dimensions are active within the sphere of her expression and creativity) Saturn and Neptune in Leo (maybe she was able to connect with the boundless and fluid Neptunian energy and harness it and use it - Saturn - as a means of creative expression. Also note these two fall in the sixth house of refinement. Midheaven/north node in Sagittarius, and Chiron in Aries. An aspiration throughout her entire life to achieve union with her earthly body and higher mind, using her earthly body as a means of communicating her truth and the essence of the divine. Wound/healing related to the identity/ego. Her expression as an artist is what motivated her to perform and attain the perfection of self that most, if not all, dancers aspire to achieve.
Rudolf Nureyev has Mercury, Venus and Saturn all in tight conjunction in Aries in his tenth house of career/vocation. Sun in Pisces is also conjunct his Midheaven. He also has his north node in Scorpio in the fifth house.
I think that fire relating to the expression of physical energy plays a rather large factor in the charts of dancers. They are athletes of the elite kind after all.
Another dominant energy in these three chart I could see was Taurus and other earth signs. Taurus/Venus archetype (perhaps even Libra) I think is a rather important factor to look out for. Aesthetics of line, performance and technique all fall within this sphere of Venusian influence.
Nureyev has Mars/Uranus in Taurus (eleventh house - message to humanity?) as well as his Moon in Libra.
Pavlova's ascendent is in Taurus, as is Chiron, Uranus and Pluto.
Fonteyn has her Mercury and Mars in Taurus.
I'm tired now.. Might finish this later .