They don't, its because AC is a limited area, its a small confined arena with a space superiority vessel included, a hornet, a raw combat fighter, verses a BMW, the insane M50, the fiesta (Aurora) ect ect. The PU will be significantly different, an expansive area, infact with a 64x game eninge, we'd literally be able to travel the distance between the planets.
So yea, take that into account, its not the gameplay, its the maps.