That's true but FTG doesn't give him the ability to notice and then react to A's speed, that's all Minato's doing. Also, I don't think Minato's dodge of the A is not as simple as you put it. In that one scan, Minato acknowledged the Raikage's movement, threw his kunai vertical to his position after noticing A's movement, waited til the last second before teleporting and then teleporting back to the same position going in for the kill. A sharingan doesn't give the user reflexes like those, Minato was also able to take on a 3T/MS user without being touched and reacting faster than Obito.