-yeap, every plot point from the beginning to now is started by either Luffy, Zoro or Nami
-Sure Robin will have a major role in the coming chapters but just you watch as she will be in a group with Luffy or Nami or Zoro, i mean even now its Luffy's group and Nami's group and Zoro's group, all other SHP even if they have to do something important and focus will be on them they will always be overshadowed by the main 3.
-Even in Sanji's arc, the driving force was Nami and Luffy, even when Oda does his where everyone is, if the SHP are split up they will be divided into Luffy's group, Nami's group or Zoro's group, you wont ever see Oda saying Sanji's group or Robin's group etc
-sure Sanji gets the 3rd best fights and thats understandable because he is the 3rd most important when it comes to fighting