By the way, it should be noted, just because a blade is a defensive blade does not mean it is a slow blade. There are plenty of defensive blades that are defensive because of the size which makes it easier to receive the ball but the blades are still fast.
Offensive blades have smaller heads because, if the blade is too big, it is harder to swing fast enough to make offensive shot after offensive shot. Still, it can be done. One of those blades with a giant blade face will feel really really good. You will get way more blade feel than from a smaller head size.