If Oda can make Luffy like Tama enough to give her his hat only one chapter after meeting her, what was stopping him having Luffy fight for his supposed future crewmate
Franky actually bonded with Robin and Usopp in a meaningful way. Yamato on the other hand hasn't done that with any Strawhat, including Luffy
He
also wanted Sanji to join his crew silly. He had been pestering him for a while about it actually
Did you forget the scene where Luffy protected Hiriluk's flag from Wapol?
And just like Yamato that tree didn't join the crew.
You realize you shot your argument in the foot here, right?
Besides it's not as though Luffy
doesn't fight for his future crewmates. He does all the time actually
You're forgetting that Luffy isn't the one writing the story here
Bro Yamato's and Luffy interactions after he woke up are on the same level as WCI Carrot
And just like Carrot, Yamato isn't joining