Vader and Anakin move and fight completely different. You can't just give Vader an Anakin Skin. You would have to change everything else too. Or do you want an Anakin who is walking and fighting like the Vader in the last Battlefront? This wouldn't work.
I have no problem with that, adds more visual variety to the game. Better than an alternate skin for Vader that looks almost exactly the same.
I have to say I also have no problem with it. Besides they could add a modifer so some powers are slightly weaker at the cost of moving quicker as I imagine darth vader (suit) will be slower moving.
