For Paulie, you had to actually be reading it weekly. Catching up on the majority of the arc and plowing through most of it just isn't the same thing, the momentum and the time to stew just isn't the same.
I was caught up with the anime as early as Alabasta, and switched over to the scans when I found out about them, when the anime was still in Skypeia. I binged through that and into the start of W7. when I found the scans was caught up a little bit into W7. I never thought it would be Kaku because the nose was just too similar to Usopp, and I didn't believe he was really going to leave forever.
But I was totally on the Paulie train for a variety of reasons. He appeared first, he had a decent design… Iceburg had basically promised one of his men if they could be convinced, after the betrayal he had no reason to stay there, his gambling and attitudes towards women gave him lots of possibilities in the group, and even as late as the big Enies Lobby battle, there were things like people asking him if he was with the Strawhats and him grudgingly accepting.
I also thought Franky was too damn weird. (Though 15 years later I understand now that "too weird" is a sign Oda put the effort in) Even up to the actual W7 fights I preferred Paulie and Franky didn't really grow on me till Thriller Bark with the pillar chucks and instant bridge... But it was pretty clearly going to be Franky after the flashback, I knew it was going to be him, I just didn't want it to be. But then the talk with Usopp, the bonding with Robin, the burning of the plans, the sea train, the color spreads, and him getting fight after fight, and showing all the variety in his skillset. There was no denying it beyond pure personal preference, he was getting huge moment after huge moment and tons of explicit bonding with the entire crew one after the other.
Brook was declared in from his first chapter, and I don't understand how anyone thought that the afro skeleton musician wasn't joining, even before Laboon.
And I was convinced very very early on with Jinbe due to all the backlog of scenes and moments and standout bits and history he got in incredibly fast order, even if I didn't care for his design or personality at first... that grew on me later, but him being an ideal candidate was pretty clear early, aside from his power level and bounty being too much, though even that was covered when it became clear there was going to be a time skip. Of course, he's STILL not around for whatever reason, I have to assume its cause he has some history in Wano and his being there at the start would have thrown something off.
I've been around this block. Carrot "has had one line of dialogue in the last year" ain't joining.