It is commonly said that the only one of the writer's novels which contains a sufficient amount of charity and sweetness is Humphry Clinker.

The statement is not quite true.

Greaves is not so strikingly amiable as Smollett's masterpiece only because it is not so striking in any of its excellences; their lines are always a little blurred.

Still, it shows that ten years before Clinker, Smollett had learned to combine the contradictory elements of life in something like their right proportions.
If obscenity and ferocity are found in his fourth novel, they are no longer found in a disproportionate degree.
There is little more to say of Sir Launcelot Greaves, except in the way of literary history.

The given name of the hero may or may not be significant.