Oda was like:
-Let me introduce a character to sail with the SH for no reason
-Let me draw 13 cats in a chapter cover to represent the SHs
-Let me draw the SHs as chinese zodiac animals but have a
dog a rabbit and a dragon left
-Let me paint luffy as a Jesus Christ figure and not have him have 12 apostles
-Let me give BB crew the name titanic, when there's 13 Titans just has there are 13 olympian gods
-Let me call only Luffy's crew, Mugiwara Ichimi (which is wordplay for 1 3 ) instead of kaizuko like every other pirate crew
-Let me have the Sunny have a massive 1 and 3 (docks) riding around the sea
-Let me introduce a character that has a
dog devil fruit and shes competing with the
rabbit mink in nakama wars
-Let me have this character with a
dog devil fruit want to join Luffy's crew
-Let me introduce a stoaway gag with this character and make her predecessors stoaway twice
-Let me have Chopper call her little sister
-Let me depicte her doing a lookout role, able to jump 100 meters in the air not needing to sleep in normal schedules and give her binoculars
-Let me give her Pedro's will to get RP, join the PK and help Luffy bring the Dawn
-Let me give her a shit king role at the end that has nothing to do with anything
-Let me give her no goodbye and give her an air of uncertainty
-Let me draw barrels for 3 chapters after
What you think any of those characters could join ? What made you think that?