The problem is, Oda hold on to "reveals" a bit too much. Whether it is power level, information, character faces (infamous shadows), etc. We still dont know who was the character that was eavesdropping or following Jinbe and Robin when they arrived at Onigashima.
Samurais fighting each other with swords would have been better as compared to that Sumo match (again what was the purpose of that character; sumo wrestler). A Sumari challenging O-Kiku, just imagine that, a proper sword fight.
There are so many quotable moments, but we, as readers, dont have any way to affect the writing/plots. It is up to the author.