Let's see...1on1, Admirals; 2on1, Admirals; 3on1, Supernovas, with extreme difficulty. The key problem is that we don't know how the other Supernovas compare to Luffy/Law/Kidd. There can huge gaps in ability like the difference in ability between Luffy and Zoro.
In the end, I'll give this fight to the Admirals. The Supernovas will put one heck of a fight, but until more of the Supernovas reach Luffy's/Law's/Kidd's level, I don't think they have what it takes to win without intel and prep.
11 vs 3 is a no brainer. Luffy, Kidd, Law, Zoro, Apoo and Killer should be enough to defeat the admirals. I don't think any one person can defeat a healthy Law and Luffy at the same time. It just doesn't seem possible.