After finishing the manga i decided to watch the anime and i noticed a fun detail (or perhaps foreshadowing) regarding the character «Dwune». 
For those who are caught up with the manga, in chapter 412 we learn about the nuances of the Kakinese language regarding pronounciation. I assume that some might feel this was an out-of-nowhere element of the story that the reader would have absolutely no way of catching beforehand as real and fake Woble’s names are spelled identically, and the Shimano/Shimanu could be passed as a localization error by the reader since Togashi is known for odd romanization of names before (another case of this is Prince Tyson vs The Taithon Canon). Its possible that the difference between the 2 Woble’s names will be possible to catch by people who listen closely to the pronounciation when the arc is animated in the future, but i do believe that many would feel that the whole name pronounciation thing is coming out of nowhere.

However! I personally believe that the concept of mishearing names was foreshadowed during the section about Dwune’s name in the end of the Greed Island arc. Without context the «My name was Wdwune (renamed to Dwune by Ging) but nobody can hear that it was spelled with a W» is nothing more than a gag, but in hindsight this could be interpreted as foreshadowing regarding the subtle writing/pronounciation of names and their importance later in the story.

I dont believe there is any evidence that Wdwune/Dwune himself is from Kakin (he is related to Luzurus trust) but i just wanted to share this observation that is easily forgotten since there is a considerable length between the Greed Island arc and The Succesion War arc.

Wdwune and Kakin [Chapter 412 spoiler]