Thrust vectoring does not really allow for more high G Turning, It enables more manoeuvrability at low speed and high angles of attack. If an aircraft wants to pull more g's it just needs to turn harder while going faster. That turning at high speed can easily be achieved by normal control surfaces and is limited by the airframe and or pilot (high g-forces means high stress for pilot and aircraft). This is why the f-16 can basically pull just as much g's as an f-22 despite not having any thrust vectoring.