The difference between the royal guard TIE and the Special Forces TIE is that one is Canon, the other is not - what i mean is this: one you will see in the movie, the other does not show up in the movies. The fact that we got a new model for the TIE/FO is pretty telling, to me, that we very well may get the TIE/FOSP (cog) as a separate model. FFG could have just painted the original TIE in the new colours.
I compared mine to the old LN; there's quite a bit of physical difference; the cockpit is bigger, the rear engine layout is different, the wing braces a beefier, and the left (looking head on) has a mall hump where antenna would go.
I th ink the COG would warrant a different model; the rear layout is different, the ground buzzer on the left brace, and the turret on the bottom.
They could go a couple of different ways with it; either a 2 attackPWT, or three attack rear aux, or two attack standard with a turret upgrade. Any iteration is bound to have crew slot for the rear facing gunner.
Dial would be like the FO, sans the green hard turns, the s loops moved up to three speed.