In 1968, those 5 matches Emerson beat Laver in, he won them all in straight sets. Think about it, beating an absolute peak laver 5 times in straight sets! What that tells me that Emerson was up there in ability. if he had gone pro in 1963, like Laver, I think he would have held his own. Emerson faded after that mainly due to age.
Don´t forget that Laver and Emerson knew each other game by memory and were so close friends.That has an effect on a particular H2H that equalizes things ( unless you are Borg and Gerulaitis, of course), specially when there is not such a big difference of level of play.