Ward-Martinez at any weight above 164 makes more sense than Floyd-Martinez at 150. Sexy has put a lot of muscles the right way and it will be very stupid and hard to boil down to 150. Ward is a small SMW so its a fair match.
You can just look at them both FFS... Historically, the jump from MW to SprMW has always been difficult. Especially when you look at their ages and there they've fought. Ward will probably grow into LtHW eventually. He's much younger. Martinez, spent his career under the MW limit until recent. He's done his growing for the most part.
Martinez could target Ward or any of the other smaller Super Six participants and make a hell of a fight. I would love to see him vs Abraham.
Barker at 160 made Maravilla look small. Ward at 168 was able to push around a very strong Carl Froch. Ward can fight at 175 easily and Martinez is pushing himself at 160. Weight classes exist for a reason.