In addition to the current. Building a humanoid robot means whatever servo's are at the base of its "appendages" need to have enough turning force to be able to support the weight of the appendiage which includes the weight of the servo mounted to the other joint.
ex: the shoulder need to be able to support the whole arm, including the weight of the elbow and wrist servos. With "the cheapest I could find" servos this may not be the case.