I think it is very likely that the Predator will be more accurate, but not because of the barrel length. But every gun is an individual, there are no guarantees and I wouldn't expect a huge difference either way. At least not at 200 yards. Get out to longer ranges and you reach a point where the extra speed from the longer barrel matters.
Between myself and 2 friends we own five Predators in 308, 6.5 CM, and 223. We also own several standard and Ranch rifles in 223, 5.56, and 308. The Predators as a rule shoot better.