Last names can be even more flexible nowadays and equivalent cultures. Candle. Green. Fairlawn. Etc.
In The High House and The False House, they are used artfully. When you have a theme, the names are a bit heavy handed. A Mr. White, Mr. Green, Mr. Black, etc. or for that matter, a Daisy, Rose, Lily, Iris, etc. make the theme elements rather heavy handed, if not actually comic. It's when you do not have a pattern -- Brittle, Hope, Chant, Murmur -- that they help suggest a deeper significance without so heavy a hand.
Of course, there's always the danger of being so portentous that the readers are frustrated when nothing moves from portending to the center stage. Names, like everything else, bring promises with them.
