Well, I think defining multiple talents should be our first step.
For starters, one can be talented in similar, interdisciplinary areas, such as in science or sport. No matter how many sports or sciences you're talented at, it's still not multi-talent, is it? It's just lesser degree of specialization. I would most often consider the best ones here to be Aries, Cancer, Libra and Capricorn (fixed signs).
Then there's the polymath type of talented, meaning you get to be talented at multiple different areas (such as science, music, literature) at the same time. Those would have to be adaptive, that is, mutable, therefore Pisces, Gemini, Virgo and Sag. They often have analytical minds which combined with multiple different interests most likely result in a polymath or a drug addict (nevermind the last one it's a joke xD).
And finally, there are the most specialized types of people who don't like to vary it around a lot. Those would be cardinal, in my opinion, including Aquarius, Taurus, Leo and Scorpio. While they don't neccessarily have just one talent, it's easily summed up with one word. Aquarius are people's people and oriented on altruism and gift economy. Anything they do will revolve around that one talent, other ones being temporary and experimental. You can easily think about all the other 11 examples based on people You know.
Also keep in mind I'm talking about modalities, which means that people will most likely have a conflict between their Sun sign/ asc and the number and position of other planets - for example, I'm Pisces/Cancer with multiple talents but with problems at focusing them at multiple areas because my other planets are mostly in Cardinal and fixed signs. Therefore, even a splash chart won't help you if it's shattered totally equally or totally unequaly; You would like your chart to cover most of the same modality not to have that kind of a conflict.