I agree. The cotton/bamboo is a considerably thinner yarn than the super soft merino. Consider also that it's a hand wash and that may not by ideal for a baby blanket. I've just finished a baby blanket in Cascade Superwash
which is a bulky (3.5sts/inch), a bit closer to your gauge and machine washable.
It's a lovely yarn, too but you'll have to check the price.