Which collection of stuff would you rather have: the first is broad, while the other is concentrated?
These are the two basic directions one can have in collecting anything. The items don’t have to be expensive; they don’t have to be particularly rare. The same question dawns upon every single collector: do I go wide or deep?
Do I collect Russian Chronographs of a particular make and decade, or do I collect all the chronographs of a particular Country of Origin or of a particular decade, for example? You could have the watch collection that follows a common rule: “no two watches from the same brand,” and have a collection that samples tastes across the horological universe.
You could go the other way, which is straight down, i.e. collecting just Rolex GMT’s, or better yet focusing exclusively on a particular movement, like a Frederic Piguet 1185 Chronograph movement. In that case you would have a collection that is deep. The reason I assert this has to do with discipline. The horizontal collection is designed to be wide, and by design, may afford more room to be impulsive. You can have a very eclectic collection that may give you a lot of meaning because it provides the collector a chance to chronicle his or her taste evolution, a joy in itself. Whereas the narrow and deep collector can say: “I have every model of X watch.” It may not sound very impressive, but what you don’t say can speak much louder. And that is you didn’t follow bunnies down rabbit holes. It says you are disciplined. The narrow, deep collector aims to speak a few languages very well; while the broad, horizontal collector wants to be conversational in as many as possible. Horizontal collectors dream of neat arrays of the “best of the best.”
When I think of the "mixed" I wish to be--I think of going vertical, not horizontal. I must go deep, and consequently I must always be thinking integratively, for the deeper I plan to bore down the more diamond-concentrated the drillbit has to be.
Ultimately that type of collector dreams of “the one.” That is, he or she dreams of the single, essential watch. That is the grail that commands monogamy, that singular, embodying example which renders all other parts of the collection redundant.