Kinich Sig or Mailed Flower

I am running mavuika melt team. Mavuika, citlali, sucrose(xilonen eventually), C6 Bennett.

While kinich's weapon has incredibly high atk. It's crit is low and passive is useless in this case. Since I have r5 mailed flower, I was wonder if it was worth going for mailed with atk sands, instead of kinich Sig with em sands.