Anyone find it a bit suspicious that Oda had to include Yamato in the same chapter as Hancock? Yamato even talks about self fulfilment with Zoro of all people. Does anyone see Yamato falling in love with Zoro the same way Hancock did with Luffy?
Hancock fell for Luffy after hearing about him punching a Celestial Dragon. Sooner or later Zoro's Oden like feats will eventually be mentioned to Yamato. I don't see any signs of Yamato falling for Luffy after he punched Kaidou into the world's core. Oda would've made it clear the same way he did with Hancock.
Even if Yamato is dead set on being Oden, Yamato would still need a Toki to truly complete the Oden tribute. My guess is Yamato and Hancock are locks to join the crew, but they need to fall in love with Zoro and Luffy before joining, as to not break Oda's no romance rule among the crew. This would put the crew at four CoC users, which would be enough to rival Rocks.