It was a naval battle, I don't take such things too seriously.
The term equal is widely used by Oda to hype characters.
You don't really expect me to believe that Garp needed training to fight Chinjao or that during Roger's era there were 100 equals sailing the seas.
Aside from Xebec the big stars were Roger,WB,Garp,Sengoku and possibly Garling.
Kaido,Meme,Shiki,Axe etc are strong but below these guys.