The 'normal neighbor/wacky neighbor' is a yin/yang relationship. If every subsequent neighbor is x-times more wacky then the next you would essentially have a lunatic asylum and the 'normal neighbor' would either go insane and become the wackiest neighbor, causing all subsequent neighbors to increase their wackiness quotent to the point of wacky implosion, or the 'normal neighbor' would simply leave, thereby causing the wacky quotient to rise on it's own, with the original wacky neighbor setting the benchmark for 'normal' in the equation, and then as mentioned above, the wacky factor would escalate to disasterous proportions.
For every one 'normal' character (or normal household), there can be no more than one wacky neighbor (or household). However, you can still have other types of neighbors such as sinister (i.e. Newman from Seinfeld), stupid (Howard Borden from The Bob Newhart Show), sexually charged (Larry Dallas from Three's Company), annoying (Urkel from Family Matters), stuck up (Carlton from Fresh Prince), dorks (Lenny and/or Squiggy from Laverne and Shirley), neighborhood snoop (Edna Cravits from Bewitched). While these and other types of neighbors could be considered 'wacky' they are not, and cannot be wacky for the sake of the show.
