I think the answer here is the number of events he shoots in, or doesn't in his case. If he didn't have a full time job and toured around like other pro-caliber players, I believe that he would win a few.
I watched him trade sets with Shane at The Carom Room in Beloit, WI. I believe they broke even after four or five hours.
I didn't see this session, but an employee of The Carom Room posted that Larry broke even with Dennis after seven hours of big table 10-ball.
I'm not trying to convince you he's going to trade sets with either player every time he plays them, but he can play with the best.
If you look at the video in the edit to my previous post, he was asked this question in an interview, and he claims he gets bored too easily in matches, which causes loss in concentration, and he hates to practice, so he doesn't do it as much as he should.
I'm not sure how you know the amount of events he plays in, or if/how long he has had a full time job, but if that's true, that could also be an explanation.
Assuming he could trade sets with Shane and Dennis on a consistent basis, then it's even more baffling that he doesn't win many of the events he plays in.