Nothing wrong with a V-style. It seems to work well for him. Not all horses are going to be "round turners". Each horse figures out his own way to turn the barrel the quickest. His turns are fine.
Make sure you are NOT looking at the barrel when you run him. Instead, look at a spot on the ground past the barrel where you want his feet to go. Focus on that spot and drive him to it. If you have to keep two hands up until that point, do it.
Doing some slow work with him will help him from anticipating. Go toward the barrel as if you are going to turn it, except don't! Instead, counter arc him away from it in the opposite direction. And THEN turn it.
Also, in slow work, you can go WAY past the barrel on purpose before you let him turn. It teaches him to wait on you for a cue.
Or you can go toward a barrel like you are going to turn it, and then simply go away from it again. Again, teaches him to wait on you.
My old horse Beau was very anticipatey. I really had to push, push him deep into the turn, and did slow work to keep him listening.
∞•*˚ Βгįťţαňγ ˚*•∞
It is not enough to know how to ride; one must know how to fall.