Most clubs purchase their motors nowadays. They are not given to them like in the past. Therefore at the end of the season they have to sell them. Lower horsepower motors are easier to sell. Many teams use 250s. Because so many use them there is a big inventory out there, making them harder to sell. Plus lower horsepower motors fit on many different types of boats. In regards to driving a triple without ballast I don't think it would be possible. Especially with the Miller hulls. Don't think they would make it off the trailer without sinking due to all the weight in the back. I think a couple teams have had that happen, or come very close to that happening. The ballast is needed to counter balance the weight. Even on my 18 when the tank was getting low you could get some good bow rise on the holeshot.
Speaking of sinking a triple. Boys and girls when there is a major rain storm coming it is suggested to take your triple out of the water. Ouch....