neji is really good for teams that rely on keeping momentum since he:
A.has hinata's mystery for free round 1 and can acupuncutre(not sure about the spelling there) turn 1
B.by placing him in the first row you can contest the first mystery(people who use naruto for example usually place him in a position for him to be the first one to attack)
hinata on the other hand shines in longer fights and is more of a stall ninja