Comparing Lassiter to Buddy is very difficult, even if it's Lassiter doing the comparison.
Lassiter's most dominant years as a hustler were in the 1940's, and his best years as a competitor were 1960-65, all of this during the straight pool era of pool. Buddy's most dominant years as a hustler were in the 1970's, and his most dominant years as a competitor were in the 1980's. Their primes did not coincide, but I've always believed that players are best measured against the players of their own era.
Lassiter was so much better than his peers at nine ball that he couldn't even get games in the early 1960's. Eddie Kelly and Harld Worst are, I'm told, the only two who would play Lassiter without weight, and they would, typically, come out on the short end. Buddy is an undeniable legend and one of the all time greats, but there were far more with a chance to beat him at his best than Lassiter ever had to deal with. By this measure, I think Lassiter rates as the greater of the two.
Still, the debate cannot resolved, and in the end, we are rightly left to admire two of the all time greats.