That's more like four types already...
We could always say that a deceptive appearance of size is one of the effects (or side effects) of using a cloak. Large ships might wish to present a smaller target but cannot become fully invisible without jeopardizing shields/sensors/power allocation/whatnot, so they apply partial power to the cloak and become smaller. And small ships might wish to appear more threatening... This also accounts for the varying size of the Defiant