Why yamato is here instead of Zoro?

Why does bandai loves yamato so much that she has 3 ex while Zoro has 1 when Zoro is stronger than her. Also they give 50 rds in her birthday and only 5 on Zoro's

Why does bandai loves yamato so much that she has 3 ex while Zoro has 1 when Zoro is stronger than her. Also they give 50 rds in her birthday and only 5 on Zoro's