Rayleigh is also a level 3 CoA user. We know this because Luffy used level 3 CoA to destroy the handcuffs. Yamato couldn't do it herself because she doesn't have ID CoA to destroy the cuffs from the inside. If Luffy used ID CoA to destroy the cuffs, then so did Rayleigh as they performed the exact same feat. Furthermore, when Luffy saved Hyo by removing the handcuffs, Hyo was shocked that he finally managed to get it right which means destroying the handcuffs is a level 3 feat. Hyo is a level 2 user, and he couldn't do it himself. So Rayleigh can also use ACoC + ID CoA.
Additionally, Sabo may also be a level 3 CoA user. He destroyed the ring from the inside. If he has awakened ACoC then he'd also go into that category. I said Shanks might because let's be real, it's Shanks. Bro's probably maxed out his Haki, especially if he's seemingly copied Roger. Garp is a solid bet too, as you acknowledged.