Heavy Throwing Axes: Purchasable but not usable?

[brave_chicken]

Heavy throwing axes are available for purchase upon taking up the Sergeant class. Heavy throwing axes have a power throw requirement of 4, but a Sergeant only has power throw of 3. I haven't bought them, but I know I can't pick up the heavy throwing axes used by Huscarls. I assume that if I purchase them as Sergeant, I won't be able to use them. They should be made to be not available for purchase until the power throw requirement is met, which is at Commando.

Perchance this was done like this so that if a person attained some points in power throw from the archer tree, they could get the axes still?