hammerhead and fantom is not a raiders

Yes they do. They just don't have turrets like scorpion/predator/pitbull. This means they shoot as soon as they enter the hex next to their target, not get to the middle, stop and shoot like non-raider units.

Also the Hammerhead will shoot twice when stationary and approached by an enemy it isn't facing to make up for the fact that it has raider.

So pay attention, and you will indeed see it they both sport raider, they just don't sport turrets 😉